储能科学与技术, 2022, 11(5): 1383-1400 doi: 10.19799/j.cnki.2095-4239.2021.0570

储能材料与器件

合金型负极预锂化技术研究进展

张策,1,2, 李思吾,1, 谢佳,1

1.华中科技大学电气与电子工程学院

2.华中科技大学材料科学与工程学院,湖北 武汉 430000

Research progress on the prelithiation technology of alloy-type anodes

ZHANG Ce,1,2, LI Siwu,1, XIE Jia,1

1.School of Electrical and Electronic Engineering, Huazhong University of Science and Technology

2.School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430000, Hubei, China

通讯作者: 谢佳,博士,教授,博士生导师,主要研究方向为电化学储能材料与器件、新型二次电池储能体系,E-mail:xiejia@hust.edu.cn

收稿日期: 2021-11-01   修回日期: 2021-12-13  

基金资助: 国家自然科学基金.  U1966214

Received: 2021-11-01   Revised: 2021-12-13  

作者简介 About authors

张策(1994—),男,硕士研究生,研究方向为电化学储能材料,E-mail:m201970850@hust.edu.cn E-mail:m201970850@hust.edu.cn

李思吾(1991—),男,博士后,主要研究方向为金属有机框架材料在电化学储能器件中的应用,E-mail:urey56@foxmail.com; E-mail:urey56@foxmail.com

摘要

负极是锂离子电池的关键组件,实现高容量合金型负极在锂离子电池中的应用可大幅提升锂离子电池的能量密度。然而目前合金型负极存在严重的低首圈库仑效率问题,致使大量活性锂在循环初期被不可逆消耗,制约了其在提升锂离子电池能量密度方面发挥优势。预锂化技术被认为是解决合金型负极锂损失问题的有效方案,主要分为负极预锂化与正极预锂化。本文通过调研整理近期相关文献,详细分析了不同预锂化技术在合金负极中的研究进展与应用前景。对于负极预锂化技术,主要介绍了电化学预锂化、接触金属锂、化学预锂化以及负极富锂添加剂等策略;对于正极预锂化技术,主要介绍了正极富锂添加剂与正极过锂化两种方法;对于不同预锂化技术的实用化,主要分析了补锂试剂稳定性与安全性、补锂试剂的利用率以及成本等问题。综合分析表明,预锂化技术是弥补不可逆容量损失、提高合金型负极锂离子电池的能量密度与循环寿命的有效方案,低成本与高安全性是预锂化技术实用化的关键所在。

关键词: 预锂化 ; 库仑效率 ; 硅负极 ; 高能量密度 ; 锂离子电池

Abstract

The anode is a key component of lithium-ion batteries, and the use of high-capacity alloy-type anodes can significantly improve the energy density of those batteries. However, alloy-type anodes suffer from low initial coulombic efficiency. This problem leads to irreversible consumption of large quantities of active lithium, which offsets the improved battery energy density. Prelithiation technology is considered a promising approach to address this problem, applicable both to anodes and cathodes. This paper summarizes research progress and application prospects for different prelithiation technologies based on a comprehensive analysis of recent literature. For anode prelithiation, the strategies of electrochemical prelithiation, chemical prelithiation, lithium-rich anode additives, and direct contact with metallic lithium, are introduced. For cathode prelithiation, strategies involving lithium-rich additives and over-lithiation are discussed. With a view toward the practical realization of different prelithiation technologies, this analysis focuses on the stability and safety, utilization rate, and cost of each prelithiation reagent. Results demonstrate that prelithiation can be an effective solution to compensate for irreversible capacity loss. Thus, it can contribute to significant improvements in energy density and cycle life of lithium-ion batteries with alloy anodes. Low cost and high safety are the keys to promote the practical application of prelithiation technology.

Keywords: pre-lithiation ; coulombic efficiency ; silicon anode ; high energy density ; lithium-ion batteries

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张策, 李思吾, 谢佳. 合金型负极预锂化技术研究进展[J]. 储能科学与技术, 2022, 11(5): 1383-1400

ZHANG Ce. Research progress on the prelithiation technology of alloy-type anodes[J]. Energy Storage Science and Technology, 2022, 11(5): 1383-1400

全球能源格局正由化石能源向清洁能源转变,我国能源结构也在向清洁低碳、安全高效方向发展,并提出了“二氧化碳排放力争于2030年前达到峰值,努力争取2060年前实现碳中和”的目标。风能、太阳能等清洁能源正强势突起,截至2020年,我国风电、光伏等新能源累计装机超过5.3亿千瓦。但风电、光伏等新能源的波动性与随机性强,亟需配套大规模储能系统。具有高能量密度、长使用寿命以及低自放电率等优异特性的锂离子电池成为目前广泛应用的能量存储器件之一。近年来,得益于新能源汽车的推广普及、消费类电子产品的快速发展以及大型储能系统的迭代更新,锂离子电池的应用需求日益增长,开发具有高能量和功率密度、高安全性和长循环寿命的锂离子电池则成为储能领域的研究热点。

具有高比容量的合金型负极如硅[4200 mAh/g (Li4.4Si)]、磷[1552 mAh/g (Li3P)]以及锡[790 mAh/g (Li4.4Sn)][1-3]被认为是下一代高能量密度锂离子电池负极的热门候选材料。然而,合金型负极的低首圈库仑效率(ICE)以及循环过程中SEI的持续破损/重建都将不可逆地消耗电池中的活性锂,降低电池的可逆容量,缩短电池使用寿命。目前,预锂化技术(图1)被认为是解决不可逆活性锂损失、提高电池能量密度与循环寿命的有效方案[4-9]

图1

图1   预锂化技术分类

Fig. 1   Classification of pre-lithiation technology


从工艺角度出发,预锂化技术主要分为负极预锂化与正极预锂化两类。负极预锂化具体是指在负极材料中预先存储一定量活性锂用以补偿首圈充电过程中SEI膜形成与其他副反应发生所造成的不可逆锂损失,或者直接使负极表面SEI膜与其他副反应预先发生以解决锂损失问题。正极预锂化具体是指在正极材料中存储额外活性锂用以补偿不可逆锂损失,以确保首圈循环之后电池内活性锂的量仍能够维持较高水平。对于预锂化技术整体发展而言,补锂试剂的稳定性、安全性以及成本是关乎预锂化技术可扩展性与实用化的关键。本文将重点研究近年来针对合金型负极开发的预锂化技术,总结分析不同预锂化技术在实用化过程中具有的优势与存在的挑战。

1 负极预锂化技术

1.1 电化学预锂化

电化学预锂化是一种常用的预锂化技术,它能够最大程度地模拟电池的化成工艺,可以通过优化电解质组分、调节外电路电流密度以及设置预锂化截止电压等途径实现电极预锂化程度和电极表面SEI膜结构与组分的调控。

目前,常用电化学预锂化技术存在工艺繁琐、环境严苛以及成本较高的问题。Kim等人[10]提出一种基于金属锂与c-SiO x 负极外短路的方案,以提高电化学预锂化的效率。具体如图2(a)所示,此方案通过外接电阻与预锂化时间调节控制预锂化速率与预锂化程度,通过电极与锂金属之间电压差值监测电极预锂化程度。然而,预锂化c-SiO x 负极静置10小时后的开路电位明显高于初始监测电位,即此监测方案不足以准确评估电极的预锂化程度。同时,Rezqita等人[13]发现对于NMC532||Si/C全电池而言(N/P=1.3∶1),Si/C负极预锂化至0.1 V(vs. Li/Li+)相较于预锂化至0.5 V(vs. Li/Li+),尽管电化学循环稳定性更好,但负极表面析锂风险提高。因此,合适的预锂化程度对电池稳定运行至关重要,不充分的预锂化无法完全弥补活性锂损失,而过度的预锂化则会提高负极表面析锂风险。

图2

图2   (a) c-SiO x 电极电化学预锂化过程示意图[10](b) 电解池预锂化原理[11](c) 牺牲电极预锂化方法示意图[12]

Fig. 2   (a) Schematic illustration of the electrochemical prelithiation of c-SiO x electrode[10]; (b) principle of the prelithiation by using electrolytic cell[11]; (c) graphical illustration of sacrificial electrode prelithiation method[12]


鉴于电化学预锂化中金属锂高活性的问题,Zhou等人[17, 20]提出一种基于无金属锂电化学预锂化方案。具体如图2(b)所示,此方案由LISICON膜桥接两个半电池构成的装置实现:含有0.5 mol/L Li2SO4/H2O的Cu阳极半电池与含有凝胶聚合物电解质/液态电解质的目标阴极半电池。电化学预锂化过程中,铜电极作为电子供体,Li2SO4作为锂离子供体。然而,由于锂离子迁移路径较长,促使电化学预锂化过程耗时较长且存在较高过电位(约0.3 V vs. Li/Li+),导致负极表面的析锂风险提高。

为提高电化学预锂化效率,JM Energy公司[21]提出“牺牲电极”预锂化方案。Watanabe等人[18]采用“牺牲电极”预锂化方案成功将磷酸铁锂/石墨体系的首圈库仑效率提高至100%。具体如图2(c)所示,未锂化的负极、隔膜与正极叠片组装,“牺牲电极”(金属锂)位于上述组件一侧并通过隔膜与电极隔开。当金属锂与未锂化的负极外电路接通时,预锂化过程随即开始。值得注意的是,“牺牲电极”预锂化方案需采用“打孔”电极,以确保锂离子在电极之间的快速迁移扩散。预锂化速率显著取决于电极开孔率以及孔径,在一定的电极开孔率条件下,预锂化速率随着孔径缩小(孔径由200 μm降至20 μm)而提高,然而预锂化过程还需要较长时间平衡各电极的预锂化程度。对于合金型负极而言,锂化过程体积膨胀显著,孔径、开孔率以及预锂化程度平衡等问题仍需深入研究。

总的来说,电化学预锂化方案能够最大程度地控制电极材料的预锂化行为,例如预锂化程度,此参数涉及正负极容量平衡(N/P比)以及电池循环过程中的安全问题(如负极表面析锂)。然而,预锂化后的电极稳定性差,导致电池的生产环境受限于惰性氛围。“牺牲电极”方案可以保证整个预锂化过程中电池与电极的完整性,且只需在干燥室中增加一个组装金属锂的工步。但该方法仍面临以下问题:①预锂化速率慢;②“打孔”电极制备成本高;③电极预锂化程度平衡耗时长。

1.2 接触金属锂预锂化

接触金属锂预锂化是指在电解质存在的条件下,负极与金属锂物理接触而实现预锂化的一种方法。由于金属锂与负极材料之间的电势差,金属锂中的电子在电场作用下迁移至负极材料,锂离子从锂金属中脱出经电解质迁移至负极材料以达到电荷平衡,最终负极材料完成补锂。如图3(a)所示,电解质提供离子传输通道,金属锂与负极材料的物理接触提供电子传输通道[14]

图3

图3   (a) SiNWs预锂化机理图[14](b) SiNWs预锂化前后的首圈电化学性能[14](c) Si粒径对Si/C复合电极预锂化行为影响示意图[15](d) 电阻缓冲层(RBL)调控预锂化进程示意图[16]

Fig. 3   (a) Schematic diagrams of the prelithiation of SiNWs electrode[14]; (b) the first cycle electrochemical performance of SiNWs before and after prelithiation[14]; (c) graphical illustration of the impact of Si particle size on the prelithiation behavior of Si/C composite electrode[15]; (d) schematic illustration of RBL(resistace buffer layer)-regulated prelithiation process[16]


Liu等人[14]采用接触金属锂预锂化方案补偿硅纳米线(SiNWs)约2000 mAh/g的容量,如图3(b)所示。Shellikeri等人[17]发现金属锂的几何形状对预锂化过程的反应动力学存在显著影响:10~30 μm的稳定锂粉的预锂化速率高于45 μm的锂带与15~20 μm的锂箔。Bärmann等人[15]研究发现对于Si/C电极而言,Si粒径越小(粒径:6.57 μm、760 nm与140 nm),Si/C电极预锂化速率越快、预锂化程度越均匀,如图3(c)所示。然而,接触金属锂方案中电子转移仅发生在金属锂与电极的接触点处。鉴于此,MENG等人[16]提出RBL电阻缓冲层(resistance buffer layer)策略,以解决金属锂或电极由于表面纹理粗糙而导致预锂化程度不均匀的问题,如图3(d)。RBL具体为PVB包覆的碳纳米管薄膜,其中PVB起内阻调节、改善预锂化速率的作用,碳纳米管薄膜起电子导通、促进均匀预锂化的作用。文献中也报道了接触金属锂预锂化应用在其他负极上的相关研究,如SnO2/C[18]、Si-Ti-Ni[19]、TiO x -Si-TiO x[20]、Si/SiO2/C[21]、Al[22]、Si[23-25]以及Si[26]等,均有效弥补了目标电极的不可逆活性锂损失、提高了全电池的能量密度与循环寿命。

综合分析,金属锂的几何形状、电极材料的组成与尺寸以及金属锂与电极的接触行为对预锂化速率与预锂化程度均一性存在显著影响。然而,尽管接触金属锂预锂化具有方法简便、可操作性强等优点,但也面临诸多亟需解决的难题:①电解液、金属锂以及预锂化后的电极稳定性差;②预锂化速率、预锂化程度的调控;③金属锂的剥离残留。

1.3 化学预锂化

化学预锂化是指采用具有强还原能力的含锂试剂,通过氧化还原反应将自身活性锂转移至目标电极材料中以实现预锂化。目前,已报道的化学预锂化主要分为固相反应法、溶液浸泡法和机械辊压法。

固相反应法,具体是指通过球磨或加热等方式实现固相电极材料与固相锂源反应实现补锂的一种方法[27, 30-33]。Ma等人[30]以LiH作锂源、Si作电极材料,经高温烧结LiH分解释放活性锂实现Si基材料预锂化,如图4(a)所示。相较于固相反应法,溶液浸泡法操作更简便,预锂化速率更快,且预锂化程度更均匀。Scott等人[34]最早采用丁基锂处理炭黑负极,然而丁基锂的高氧化还原电位(约1 V vs. Li/Li+)无法满足合金型负极的补锂需求。Wang等人[28, 35]开发出氧化还原电位低至0.41 V(vs. Li/Li+)的Li-Bp/THF作为补锂试剂,成功预锂化P/C电极,同时Li-Bp/THF还可形成钝化膜提高预锂化电极稳定性,如图4(b)。类似于Li-Bp/THF,Shen等人[29]提出采用氧化还原电位低至0.35 V(vs. Li/Li+)的Li-Naph/DME预锂化S-PAN与Si电极,如图4(c)。构筑能量密度高达710 Wh/kg的Li2S-PAN||Si(部分预锂化)全电池,循环50圈后的容量保持82.6%。

图4

图4   (a) DSM-Si制备工艺示意图[27](b) 联苯锂(Li-Bp)预锂化负极过程示意图[28](c) 萘基锂(Li-Naph)预锂化示意图[29]

Fig. 4   (a) Schematic diagrams of the preparation procedure of DSM-Si[27]; (b) schematic diagrams of the prelithiation procedure of negative electrode by Li-Bp[28]; (c) schematic illustration of Li-Naph prelithiation[29]


然而,Li-Bp/THF与Li-Naph/DME的氧化还原电位均>0.3 V(vs. Li/Li+),低于Si的SEI膜形成电位约0.5 V(vs. Li/Li+)而高于Si的锂化电位约0.2 V(vs. Li/Li+),无法锂化Si基负极,即无法弥补Si基负极膨胀过程中SEI膜破损/重建所消耗的活性锂[28-29, 35, 40-43]。Jang等人[36]从分子结构角度出发,于联苯分子上引入供电子甲基基团以降低分子的电子亲和性,从而提升预锂化试剂的还原能力,成功开发出一种氧化还原电位低于0.2 V(vs. Li/Li+)、适用于Si基负极的锂-联苯衍生物预锂化试剂(LAC),如图5(a)。锂-联苯衍生物的氧化还原电位与依据密度泛函理论(DFT)计算的联苯衍生物的最低未占据分子轨道(LUMO)能级线性相关。此外,锂-联苯衍生物的氧化还原电位还与温度线性相关:dE1/2/dT=-2.6 mV/K,温度由10 ℃提升至50 ℃,氧化还原电位由231 mV降至129 mV。同时,HUANG等人[44]开发出一种氧化还原电位低至0.22 V(vs. Li/Li+)的Li-DiMF/THF预锂化试剂。

图5

图5   (a) Li-Bp复合物氧化还原电位对硅基负极化学锂化与SEI膜形成的机理示意图[36](b) Li-BpDMETHF2-Me-THF三种醚中分别形成的Li-Bp-溶剂络合物的几何构型和HOMO能级以及循环伏安曲线[37](c) Li-BpDMETHP中形成的Li-Bp-溶剂络合物的几何构型[38](d) 对辊预锂化Sn电极方法示意图[39]

Fig. 5   (a) Schematic diagram describing chemical lithiation of Si-based anodes and SEI formation depending on redox potential of the Li-BP complex[36]; (b) geometrical configurations and HOMO energy levels of the Li-Bp-solvent complexes formed by Li-Bp in three ethers solvent of DME, THF, and 2-Me-THF, respectively[37]; (c) geometrical configurations of the Li-Bp-solvent complexes formed by Li-Bp in three ethers solvent of DME and THP[38]; (d) schematic illustration of roll-to-roll prelithiation method on Sn electrode[39]


相较于纯Si基电极,Si/C复合电极是提高锂离子电池能量密度并保证长循环寿命的有效方案[45]。然而,常规的醚类溶剂(如THF、DME与DEGDME等)与石墨兼容性差,存在溶剂共嵌入行为。鉴于此,Shen等人[37]开发出氧化还原电位低至0.08 V(vs. Li/Li+)、满足石墨预锂化需求的Li-Bp/2-Me-THF试剂,主要归因于溶剂2-Me-THF的高配位数、大空间位阻以及强给电子能力,在解决溶剂共嵌入问题的同时降低预锂化试剂的氧化还原电位,如图5(b)。Choi等人[38]发现弱溶剂能够增强Li+-阴离子相互作用,限制自由溶剂-离子的形成,从而避免石墨电极的溶剂共嵌入,如图5(c)所示。

最近,研究人员[39, 46-50]提出采用机械辊压预锂化合金类电极的方案。如图5(d)所示,以Sn电极为例,研究人员采用100 μm Sn箔与50 μm Li箔为原料,经过30 MPa压力下辊压反应,最终制得30 μm厚的Li x Sn合金层。机械辊压法中辊压压力对于合金层的构建至关重要:压力过低导致反应不彻底,表面残留金属锂;压力过高破坏电极结构。

尽管机械辊压法能够有效匹配商用电极辊压工艺,但存在适用范围小的问题。同时,相较于固相反应法,溶液浸泡法能够实现电极材料的均匀、快速预锂化,且可通过控制浸泡时间与浸泡温度调控电极材料的预锂化程度。然而,由于预锂化试剂的高反应活性,试剂制备、存储与应用中涉及的安全问题以及预锂化电极的清洗、存储与组装等问题均需考虑。同时,预锂化试剂与电极各组分的匹配问题仍需深入研究分析。

1.4 富锂添加剂

富锂添加剂在电池运行期间能够有效释放存储的活性锂用以弥补不可逆锂损失。目前已报道的富锂添加剂包括:锂金属类(如SLMP、CLP与OPA@Li-CNT等),以及锂化活性物质类(如Li2O@Li x Si、人造SEI膜@Li x Si与Li x Si/Li2O等)。

金属锂被认为是理想的添加剂,归因于其高理论比容量(3860 mAh/g)、低氧化还原电位(-3.04 V vs. Li/Li+)[53]以及无残留的特性。然而,金属锂质软、密度低,用于补锂的低面容量超薄锂箔制备工艺复杂、难度高。相较于超薄金属锂,锂粉的可操作性提升,但反应活性也随之提高。FMC公司提出碳酸锂包覆方案(SLMP)提高锂粉稳定性[54-55],SLMP主要由约97%的金属锂与约3%碳酸锂组成,尺寸为5~50 μm。然而,Forney等人[51]发现Li2CO3在保护锂金属的同时会抑制SLMP补锂功效,静压工艺是活化SLMP的有效手段,如图6(a)、(b)所示。与此同时,其他研究团队也相继开发了类似策略,如Rockwood[56-57]提出的有机组分(如脂肪酸/脂肪酸酯)包覆稳定锂粉(CLP)工艺、Kang等人[58]提出了十八烷基磷酸(OPA)包覆稳定Li-CNT球工艺以及Li等人[59]开发的电镀包覆LiF/Li2O壳层(厚15 nm)稳定超细锂球(0.5~3 μm)工艺等,以上策略均取得了一定的保护效果与金属锂可操作性的提升。以SLMP为例,目前电极制备过程中采用的溶剂(如N-甲基吡咯烷酮、二甲基甲酰胺、二甲基乙酰胺以及水)为极性分子,能够与SLMP反应。针对这一问题,研究人员提出SLMP-SBR-甲苯悬浮液[60]、PS-SBR/二甲苯[61]、聚异丁烯/庚烷[56]以及PVDF-SBR[62]等方案实现SLMP的均匀稳定分散,主要归因于上述方案采用无质子氢惰性溶剂,质子氢会与高活性金属锂反应。此外,Seong等人[63]提出构建双层电极/集流体的设计,Cao等人[64]提出采用聚甲基丙烯酸甲酯(PMMA)包覆层方案以解决金属锂与极性溶剂的接触反应问题。

图6

图6   (a) SLMP压力活化示意图[51](b) 压力活化对SLMP预锂化作用的影响[51](c) 微米级锂源薄膜的设计与制备流程图[52]

Fig. 6   (a) Cartoon of the effect of pressure-activation of the SLMP[51]; (b) the effect of pressure-activation on the SLMP prelithiation[51]; (c) schematic illustration of design and fabrication process of micrometre-scale lithium source[52]


近日,Chen等人[52]提出锂金属-氧化石墨烯(Li@eGF)以解决低面容量超薄金属锂的工艺难题。具体步骤如图6(c)所示,辊压制备厚度可调(0.3~20 μm)的氧化石墨烯骨架,结合熔融灌锂制备低面容量补锂箔材(面容量:0.1~3.7 mA/cm2)。此外,Li@eGF发挥效用后的氧化石墨烯骨架还可以缓解Si电极的体积膨胀效应,综合提高Si电极的循环寿命。

除金属锂外,锂化活性物质也可作为负极预锂化试剂。硅本身作为下一代高能量密度锂离子电池极具潜力的负极材料,高比容量的特性促使锂化的硅(Li x Si)成为一种高效补锂材料。与金属锂相似,Li x Si也存在稳定性不足的问题。Zhao等人提出Li x Si表面包覆Li2O(Li2O@Li x Si)[65]、人造SEI膜包覆(人造SEI膜@Li x Si)[66]策略,如图7(a)与(b)。相较于Li2O@Li x Si,人造SEI膜@Li x Si稳定性更佳,置于干燥空气中5天容量保持率约100%,归因于人造SEI膜由具有长疏水链的烷基碳酸锂与LiF构成。然而,表面包覆通常存在致密性不足的问题,Zhao等人[67]从结构设计的角度出发,构建Li x Si纳米颗粒均匀分散于Li2O基体中的Li x Si/Li2O复合物提高材料稳定性,如图7(c)所示。具体原因:即使部分活性Li x Si纳米颗粒由于包覆层致密性不足而失活,Li2O基体中剩余Li x Si纳米颗粒仍具备反应活性。同时,Li x Z-Li2O纳米颗粒(Z=Sn或者Ge)的稳定性分别优于Li x Si-Li2O,主要归因于Ge-Li(-2.98 eV)与Sn-Li(-2.15 eV)的结合能远高于Si-Li(-0.8 eV)[68],如图7(d)所示。

图7

图7   (a) 干燥空气稳定的Li2O@Li x Si纳米颗粒结构示意图[65](b) 人造SEI膜包覆Li x Si NPs示意图[66](c) Li x Si/Li2O复合物结构示意图[67](d) Li分别与SiGeSn的结合能(Eb)[68]

Fig. 7   Schematic illustration of (a) the structure of lithium silicide-lithium oxide nanoparticals(Li2O@Li x Si NPs)[65]; (b) the artificial SEI coating formed on the surface of Li x Si NPs[66] and (c) the structure of Li x Si/Li2O composite[67]; (d) the binding energy (Eb) of Li with Z (Z = Si, Ge and Sn)[68]


锂金属(如SLMP)以及锂化活性物质(如人造SEI膜@Li x Si)的高比容量、低氧化还原电位以及理想状况无残留的特性,使其成为极具竞争力的补锂添加剂。然而,锂金属以及锂化活性物质的稳定性不足所涉及的溶剂/黏结剂匹配问题与工艺制备难题,以及添加剂均匀分散涉及的预锂化程度均一性的问题,均严重阻碍了二者的发展。同时,电极(含富锂添加剂)注液后,电极与添加剂反应涉及的热控制问题、电解液的消耗问题等仍需深入研究分析。

2 正极预锂化技术

2.1 富锂添加剂

正极富锂添加剂通常具备如下特征:①质量能量密度和体积能量密度远高于目前商用正极材料;②能够在正极材料电压范围内有效释放活性锂,而在正极材料的电压范围内不存储锂,即脱锂过程不可逆;③兼容现有电池制备工艺,包括正极材料、黏结剂、导电剂、溶剂、电解液以及生产环境;④发挥作用前后对电极材料、电解质以及整个电池系统的性能无负面影响。目前已报道的富锂添加剂主要包括二元富锂添加剂(如Li2O、Li2S与Li3N等)以及三元富锂添加剂(如Li2CO3、Li2C2O4与Li5FeO4等)。

二元富锂添加剂,具体是指如Li3N、Li2O、Li2O2、Li2S以及LiF等由两种元素组成的材料。其中,Li3N的理论容量(2309 mAh/g)为目前商用正极材料的10倍以上,但化学稳定性不足于常规极性溶剂反应(如NMP、H2O)。Sun等人[73]提出Li2O/Li2CO3包覆稳定方案,使包覆后的Li3N与THF等低极性溶剂兼容。Park等人[69]发现由于Li3N的分解产气以及导电性差的问题,Li3N涂覆于LiCoO2电极表面(5% Li3N)较分散于LiCoO2电极内(2%~4% Li3N)电化学性能更佳,如图8(a)。此外,Yang等人[74]提出蒸镀金属锂-氮气处理的方法于电极表面引入定量Li3N,以解决Li3N的溶剂兼容问题。Wang等人[72]提出Li3P/rGO复合物在提供额外活性锂的同时反应残留物P可作为阻燃剂提高电极的安全性能,如图8(d)所示。在不考虑制备工艺的条件下,综合分析上述工作发现Li3N的容量发挥(1319.7 mAh/g、1399.3 mAh/g与1761 mAh/g)随截止电位的升高(4.0 V、4.2 V与4.5 V,vs. Li/Li+)而提高,但均低于Li3N的理论容量(2309 mAh/g),因此Li3N的反应程度与反应残留问题还需深入研究分析。

图8

图8   (a) Li3NLiCoO2 电极表面沉积示意图以及全电池电化学性能[69](b) M/Li2O添加剂制备示意图[70](c) Li2S-PAN浆料以及LFP/Li2S-PAN复合电极的制备示意图[71](d) Li3P/rGO复合物用作正极补锂添加剂示意图[72]

Fig. 8   (a) Schematic illustration of Li3N deposition on the LiCoO2 surface and full cell performance[69]; (b) schematic structure of the preparation of M/Li2O additive[70]; (c) schematic diagram of the preparation of Li2S-PAN slurry and LFP/Li2S-PAN composite electrode[71]; (d) schematic diagram of Li3P/rGO complex used as cathode lithium supplement additive[72]


除此之外,针对Li2O2、Li2O、Li2S以及LiF等补锂试剂,尺寸与导电网络优化、催化剂引入以及调整反应路径是提高其电化学活性的常用手段。Zhan等人[75-76]提出构建以KB为核、Li2S为壳(厚12 nm)的复合材料提高Li2S的反应动力学,其在2.5~3.8 V(vs. Li/Li+)电压范围内可提供1084 mAh/g(S)的不可逆容量。BIE等人[77]以球磨6 h的NCM111(NCM-6h)作催化剂成功将Li2O2(尺寸为0.2~1 μm)的分解电位降至4.2~4.3 V(vs. Li/Li+)。Sun等人[70]提出通过调整Li2O反应路径的方式提高Li2O反应动力学,反应路径如下:MxOy + 2yLi  xM + yLi2O  MxOy + 2yLi+ + 2ye-。M/Li2O纳米复合材料(M=Fe、Co以及Ni等)通过过渡金属氧化物与熔融金属锂反应制备,其中纳米过渡金属的存在将Li2O的分解反应转为转换反应,如图8(b)。LiF与Li2S均可利用此方案提高反应动力学[78-80]。Liu等人[71]从分子结构角度出发以Li2S-PAN作为补锂添加剂,在提高Li2S反应动力学的同时,改善Li2S的酯类电解液兼容性、降低多硫化物穿梭效应,如图8(c)。近日,Du等人[81]结合M/Li2O中MO x 导电性高、反应动力学快的优点与M/LiF中M—F键高离子性的优点制备稳定性优异的Fe/LiF/Li2O纳米复合材料(比容量527 mAh/g)。值得注意的是,Abouimrane等人[82]发现Li2O的分解行为受电解液与电流密度的影响:在3 mA/g电流密度下,Li2O的利用率在1 mol/L LiClO4 EC∶EMC(3∶7,质量比)与1.2 mol/L LiPF6 EC∶EMC(3∶7,质量比)中分别为68%和39%;在1 mol/L LiClO4 EC∶EMC(3∶7,质量比)电解液中,Li2O的利用率在电流密度3 mA/g与10 mA/g下分别为68%和28%。

三元富锂添加剂,具体是指如Li2C2O4、Li2CO3以及Li5FeO4等由三种元素组成的材料。Shanmukaraj等人[86]发现酮基丙二酸锂(Li2C3O5)、双酮基丁二酸锂(Li2C4O6)以及草酸锂(Li2C2O4)的分解电位随着分子内羰基数量的增多而降低,主要归因于羰基为吸电子基团,可以降低分子的电子态密度,提高分子的HOMO能级,从而降低材料分解电位。近日,Zou等人[83]基于Kolbe反应开发出了一种金属羧酸盐类添加剂,该添加剂的氧化分解电位由氧-金属键的键能控制:给电子效应的取代基与低电荷密度的阳离子可显著降低氧-金属键的键能,进而提高其电化学活性,如图9(a)。Wang等人[87]通过煅烧法制备的NiO-Li2CO3复合材料(晶粒尺寸约40 nm,一次颗粒尺寸20~50 nm,二次颗粒尺寸200~500 nm),Li2CO3分解电位为4.4 V(vs. Li/Li+),高于脉冲激光沉积工艺制备NiO-Li2CO3复合薄膜电极(晶粒尺寸5~8 nm,电极厚225 nm)分解电位4.1 V(vs. Li/Li+),主要归因于煅烧法制备的NiO-Li2CO3复合材料的大粒径降低了复合材料的反应动力学。Fan等人[84]将纳米LiCoO2与Li2CO3(1∶1,质量比)均匀复合,利用高价态Co优异的催化效用将Li2CO3的分解电位降至4.25 V(vs. Li/Li+),如图9(b)。Solchenbach等人[85-86]成功将Li2C2O4应用于高压镍锰酸锂(LiNi0.5Mn1.5O4),通过原位电化学质谱研究发现分解电位高至4.7 V(vs. Li/Li+),如图9(c)所示。然而,复合材料中催化剂/导电剂/黏结剂等非活性物质组分占比太高在提高材料反应动力学同时降低了高比容量优势,因此高容量锂碳氧化合物类材料的应用仍需进一步探索。

图9

图9   (a) O—M键能调节的机理图[83](b) LiCoO2 催化Li2CO3 分解示意图[84](c) Li2C2O4 电化学氧化分解的比容量/电压曲线[85]

Fig. 9   (a) Mechanistic diagram of the principle of modulating the bonding energy of O—M moiety[83]; (b) schematic diagram of Li2CO3 decomposition catalyzed by LiCoO2[84]; (c) specific capacity-voltage curve and gas evolution of the electrochemical oxidation decomposition of Li2C2O4[85]


与此同时,研究人员相继开发多种三元富锂过渡金属氧化物类材料,如Li6CoO4(比容量:305 mAh/g)[88]、Li2NiO2(比容量:257 mAh/g)[89]、Li2MoO3(比容量:232 mAh/g)[90]、Li5ReO6(比容量:410 mAh/g)[91]与Li2CuO2(比容量:320~340 mAh/g)[92]以及Li5FeO4[93-94]。然而,富锂过渡金属氧化物作为正极补锂试剂脱锂后反应产物残留等一系列问题均严重阻碍了其作为正极预锂化试剂实用化进程。

整体来说,由于富锂添加剂具有较高的氧化还原电位,因此相较于负极预锂化方案中采用的锂源表现出更为优异的稳定性,同时多种富锂添加剂能够兼容正极制浆所用的NMP溶剂。然而,富锂添加剂的反应动力学差的问题、反应程度控制的问题以及发挥补锂效用后反应物残留的问题给其实际应用带来诸多障碍。

2.2 正极过锂化

正极过锂化,顾名思义正极材料在无添加剂条件下存储额外活性锂处于过度锂化的状态。额外活性锂经首圈充电过程脱出后,由于动力学的限制后续循环过程中无法可逆嵌回正极材料中,这种“动态丢失”的容量能够用以弥补不可逆活性锂损失。

尖晶石型LiMn2O4四面体位点能够可逆嵌入一个Li+(约4 V vs. Li/Li+),八面体位点能够可逆嵌入第二个Li+(2.8 V vs. Li/Li+)。Aravindan等人[95]通过电化学方法于LiMn2O4的八面体位点存储额外活性锂,如图10(a)。镍锰酸锂LiNi0.5Mn1.5O4同样可以利用八面体位点在2.8 V(vs. Li/Li+)电压下存储一个锂离子,后续循环利用四面体位点在4.7 V(vs. Li/Li+)电压下实现锂离子的可逆嵌入/脱出过程。Dose等人[96]采用液氨-锂作为锂源处理LiNi0.5Mn1.5O4制备具有不同过度锂化程度的Li1+x Ni0.5Mn1.5O4(x=0.26、0.35、0.44、0.62)。额外锂源能够在3.8~4.0 V(vs. Li/Li+)内有效脱出活性锂,如图10(b)。然而,LNMO随着过锂化程度的提高放电容量逐渐降低,由124 mAh/g(Li1.04Ni0.5Mn1.5O4)降至102 mAh/g(Li1.62Ni0.5Mn1.5O4)。具体原因如下:①过锂化LNMO的姜-泰勒效应会造成严重的离子混排(姜-泰勒活性Mn3+在Li1.62Ni0.5Mn1.5O4中高达42%;②由于锂离子在八面体位点脱出过程伴随立方相与四方相之间的相转变,相应的相变会破坏LNMO的尖晶石结构,且内应力造成的微裂纹则会进一步致使活性物质失效。

图10

图10   (a) LiMn2O4 的电化学性能[95](b) Li1.04NMOLi1.62NMO的首圈充电曲线[96](c) LR-Ni65||Si/graphiteNi65||Si/graphite 软包电池的电化学性能以及LR-Ni65 的结构示意图;(d) Li3V2(PO4)3 的首圈充放电性能[97]

Fig. 10   (a) Electrochemical performance of LiMn2O4 in half-cell configuration. Insert: cycling performance[95]; (b) the first charge curves of Li1.04NMO and Li1.62NMO in half cells[96]; (c) electrochemical performance of LR-Ni65||Si/graphite and Ni65||Si/graphite pouch cells and the cartoon of the structure of LR-Ni65; (d) the first cycle performance of Li3V2(PO4)3 in half cells[97]


α-NaFeO2型富锂层状氧化物能够在表面/体相中存储额外活性锂而不会导致键的断裂与整体结构的坍塌,同时适度的Li/Ni混排还可以提高3a位点的非活性Ni2+的含量进而提高富锂层状氧化物的结构稳定性[98-100]。Liu等人[101]采用萘基锂浸泡LiNi0.65Mn0.2Co0.15O2(Ni65),Ni65表面的Ni3+还原为Ni2+并伴随Li+的嵌入,达到构建富锂梯度界面调控Li/Ni无序程度以及提供额外活性锂的双重作用。化学预锂化Ni65(LR-Ni65)在约2.0 V(vs. Li/Li+)可额外释放活性锂24 mAh/g,其LR-Ni65/Si-石墨全电池在1 C条件下循环400圈的容量保持率为82.6%,如图10(c)。Liu等人[102]通过萘基锂浸泡化学预锂化方法在LiCoO2表面原位构建Li2O/Co补锂层(约20 nm),其初始充电容量为165 mAh/g(空白LiCoO2:150 mAh/g)。

单斜结构的Li3V2(PO4)3,具有更高的安全性与锂离子扩散系数,其脱锂过程如下:Li3V2(PO4)3 Li2.5V2(PO4)3 Li2V2(PO4)3 LiV2(PO4)3。Liu等人[97]提出首圈利用Li3V2(PO4)3中一个Li+用于补锂、循环以Li2V2(PO4)3与LiV2(PO4)3之间的转化为主的补锂方案,如图10(d)。相比Li3V2(PO4)3,尽管Li5V2(PO4)3能够提供更高容量(约137 mAh/g),但空气稳定性太差(置于空气12 h后容量由约205 mAh/g降至70 mAh/g)[103]

针对过锂化正极的制备方法,目前研究人员已开发多种正极过锂化方法包括:萘基锂[101-102]、戊醇锂[104]、丁基锂[105]、液氨锂[96]、LiI/乙腈[106]、LiOH[107]等的化学方法,但均存在采用的锂源稳定性不足的问题。鉴于此,Moorhead-Rosenberg等人[108]开发出一种微波辅助化学过锂化LNMO的方法,该方法采用四甘醇(TEG)为还原剂,以水合LiOH为锂源,无需惰性气氛就可以有效解决锂源高还原性的问题。

正极过锂化能够额外存储活性锂离子以弥补电池的不可逆活性锂损失,无需引入正极富锂添加剂或者负极补锂策略,是一种有效的预锂化方案。然而,过锂化正极的补锂容量通常低于150 mAh/g,对锂损失较大的电池体系存在补锂容量不足的问题,同时过锂化过程中正极材料的相变问题对电极的循环稳定性也提出了新的挑战,同时目前正极材料的可选择性较低。

3 总结

高能量密度锂离子电池的开发成为储能领域的研究热点,具有高比容量的合金型材料被认为是极具潜力的下一代负极。预锂化技术被认为是解决不可逆活性锂损失,提高电池能量密度与循环寿命的关键技术。近年来,负极预锂化技术与正极预锂化技术均得到长足发展,而不同的预锂化技术具有各自的优势与不足。为了清晰分析不同预锂化技术的补锂效果,表1对比分析了负极预锂化方案中不同锂离子电池系统预锂化前后的首圈库仑效率以及循环性能,表2对比分析了正极预锂化方案中不同预锂化试剂的补锂容量以及添加剂对电池电化学性能的影响。

表1   负极预锂化前后锂离子电池的电化学性能对比

Table 1  The comparison of electrochemical performance of the Li-ion batteries before and after anode pre-lithiation

负极方法电池体系预锂化前ICE预锂化后ICE循环性能参考文献
c-SiO x电化学NCA||c-SiO x58.85%85.34%61%(1 C, 100圈)[10]
SiO x接触金属锂NCM622||SiO x68%87%74%(200圈)[16]
P/C

Li-Bp/THF

0.41 V (vs. Li/Li+)

P/C||Li74%94%[28]
SiO x /C

Li-Bp/THF

0.41 V (vs. Li/Li+)

SiO x /C||Li75.6%90%~58%(0.5 C, 400圈)[40]
Si

Li-Naph/DME

0.35 V (vs. Li/Li+)

Si||Li74%96.1%[29]
SiO x

Li-Arene

<0.2 V (vs. Li/Li+)

NCM532||SiO x37.8%86.4%[36]
c-Gr/Si

Li-Bp/2-Me-THF

0.08 V (vs. Li/Li+)

NCM622||

c-Gr/Si

63.2%88.3%87.3%(250圈)[38]
Sn机械辊压LFP||Sn21%94%94.5%(200圈)[39]
Si-CNTSLMPSi-CNT||Li58%79%[51]
SiLi@eGFSi||Li79.4%100.5%56%(0.05 C, 100圈)[52]
SiLi x Si-Li2OSi||Li76%94%[65]

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表2   正极预锂化方案中预锂化试剂的补锂容量以及对电池性能的影响

Table 2  Thedonorcapacity of cathode pre-lithiation reagent and its impact on battery performance

补锂试剂容量电池补锂前首圈充电容量添加量/(%,质量分数)补锂后首圈充电容量参考文献
Li3N

1399.3 mAh/g

(截止电位4.2 V)

LCO||Li149.7 mAh/g2178.4 mAh/g[69]
Fe/LiF/Li2O

550 mAh/g

(截止电位4.4 V)

NCM622||Li198 mAh/g4.8229 mAh/g[81]
Li2S-PAN

668 mAh/g

(截止电位4.0 V)

LFP||Li169 mAh/g4.3187 mAh/g[71]
Co/Li2O

619 mAh/g

(截止电位4.1 V)

LFP||Li163 mAh/g4.8183 mAh/g[70]

Li3P/rGO

(5:1)

1289.7 mAh/g

(理论)

LFP||Li162 mAh/g5181.3 mAh/g[72]
Li5FeO4

764 mAh/g

(截止电位4.7 V)

NCM523||Li190 mAh/g7.1233 mAh/g[94]
NiO/Li2CO3

240 mAh/g

(截止电位4.5 V)

LMO||Li120 mAh/g50410 mAh/g[87]
Li1.62Ni0.5Mn1.5O4截止电位4.55 VLMO||Li145 mAh/g217 mAh/g[96]

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从成本、安全性、能量密度以及可控性四个维度综合分析不同预锂化技术各自的实用化潜力,具体如图11所示。以“牺牲电极”方案为代表的电化学预锂化,在预锂化程度可控性与工艺兼容性方面具有一定优势,仅需增加一个组装金属锂的工步,但该方法补锂速率过慢耗时长,同时电极“打孔”会提高成本。接触金属锂方案是一种常用补锂手段,操作简便,但由于电解液、金属锂以及预锂化后的电极稳定性差,需在惰性氛围操作。以溶液浸泡法预锂化方案为代表的化学预锂化,尽管能够实现电极材料快速且均匀地预锂化,但补锂试剂的反应活性高,较难实用化。以超薄锂箔预锂化方案为代表富锂添加剂(负极)可有效匹配目前电池辊卷制备工艺,但电池注液后金属锂与负极之间反应造成的电池升温以及低面容量超薄金属锂难制备的问题需进一步解决。以尖晶石型LiMn2O4为代表的正极过锂化是一种有效的预锂化方案,但补锂容量通常低于150 mAh/g,无法满足高容量负极的补锂需求。以M/Li x N y (M=Fe、Co以及Ni等,N=O、S以及F等)为代表的富锂添加剂(正极),补锂容量较高、稳定性较好,同时兼容正极制浆所用的NMP溶剂。

图11

图11   不同预锂化技术特性对比,包括电化学预锂化、接触金属锂、化学预锂化、富锂添加剂(负极)、富锂添加剂(正极)和正极过锂化

*注:成本优势:补锂试剂原料成本、补锂试剂生产成本、补锂试剂存储成本、补锂试剂运输成本、补锂试剂应用成本安全性:原料安全性、生产安全性、存储安全性、运输安全性、补锂过程安全性可控性:补锂试剂生产可控性、存储保质可控性、运输稳定可控性、应用过程可控性、补锂程度可控性能量密度:补锂试剂比容量、补锂试剂“活性”比容量、补锂试剂残留物、电极结构影响、电解液损耗影响

Fig. 11   Comparison of the characteristics of different pre-lithiation technologies, including electrochemical pre-lithiation, contact lithium metal, chemical pre-lithiation, lithium-rich additives (anode), lithium-rich additives (cathode), and over-lithiated cathode


整体而言,与目前电池制备工艺兼容性更好的正极预锂化技术具有相对更高的稳定性与安全性,然而相关研究文献主要侧重补锂容量与电池能量密度提升,关于补锂试剂的利用率以及反应残留问题关注不足,如Li3N的利用率随充电截止电位的提升而提高,但均低于Li3N的理论容量;此外,Li3N反应产气后遗留的孔隙与Li3N导电性较差的问题对电池电化学性能的相关影响还需深入研究。相较于正极预锂化,基于金属锂开发的负极预锂化技术尽管存在由于金属锂稳定性不足涉及的工艺兼容性差的问题,但可以有效避免补锂试剂反应残留物的潜在影响。同时,研究人员已提出多种方案解决金属锂兼容问题,如JM公司提出的“牺牲电极”方案仅需在干燥室中增加一个组装金属锂的工步,Maxwell的干电极制备工艺排除了极性溶剂对金属锂制品的腐蚀,宁德时代提出更贴合目前电极制备工艺的具有实操性的锂粉或锂带补锂方案,上述方案均极大推动了负极预锂化技术的实用化进程。基于上述分析,基于金属锂的负极预锂化技术更具前景与优势,有望规模化应用。

总之,对于已开发的预锂化技术,试剂补锂容量与全电池能量密度的提高仍需进一步改进;更多的新型预锂化技术也要不断探索;除此之外,预锂化技术实用化关键还在于成本以及安全性。综上所述,预锂化技术的成功应用能够有效提高锂离子电池的能量密度与循环寿命,促进交通与新能源的融合,推动基于高比例可再生能源的新型电力系统的发展,助力碳中和目标早日达成。

参考文献

CABANA J, MONCONDUIT L, LARCHER D, et al. Beyond intercalation-based Li-ion batteries: The state of the art and challenges of electrode materials reacting through conversion reactions[J]. Advanced Materials, 2010, 22(35): E170-E192.

[本文引用: 1]

NITTA N, WU F X, LEE J T, et al. Li-ion battery materials: Present and future[J]. Materials Today, 2015, 18(5): 252-264.

罗飞, 褚赓, 黄杰, 等. 锂离子电池基础科学问题(Ⅷ)——负极材料[J]. 储能科学与技术, 2014, 3(2): 146-163.

[本文引用: 1]

LUO F, CHU G, HUANG J, et al. Fundamental scientific aspects of lithium batteries(‍Ⅷ)‍—Anode electrode materials[J]. Energy Storage Science and Technology, 2014, 3(2): 146-163.

[本文引用: 1]

明海, 明军, 邱景义, 等. 预锂化技术在能源存储中的应用[J]. 储能科学与技术, 2017, 6(2): 223-236.

[本文引用: 1]

MING H, MING J, QIU J Y, et al. Applications of pre-lithiation technologies in energy storage[J]. Energy Storage Science and Technology, 2017, 6(2): 223-236.

[本文引用: 1]

JIN L M, SHEN C, WU Q, et al. Pre-lithiation strategies for next-generation practical lithium-ion batteries[J]. Advanced Science, 2021, 8(12): doi:10.1002/advs.202005031.

SUN C K, ZHANG X, LI C, et al. Recent advances in prelithiation materials and approaches for lithium-ion batteries and capacitors[J]. Energy Storage Materials, 2020, 32: 497-516.

ZHAN R M, WANG X C, CHEN Z H, et al. Promises and challenges of the practical implementation of prelithiation in lithium-ion batteries[J]. Advanced Energy Materials, 2021, 11(35): doi:10.1002/aenm.202101565.

WANG F, WANG B, LI J X, et al. Prelithiation: A crucial strategy for boosting the practical application of next-generation lithium ion battery[J]. ACS Nano, 2021, 15(2): 2197-2218.

HOLTSTIEGE F, BÄRMANN P, NÖLLE R, et al. Pre-lithiation strategies for rechargeable energy storage technologies: Concepts, promises and challenges[J]. Batteries, 2018, 4(1): 4.

[本文引用: 1]

KIM H J, CHOI S, LEE S J, et al. Controlled prelithiation of silicon monoxide for high performance lithium-ion rechargeable full cells[J]. Nano Letters, 2016, 16(1): 282-288.

[本文引用: 4]

ZHOU H T, WANG X H, CHEN D E. Li-metal-free prelithiation of Si-based negative electrodes for full Li-ion batteries[J]. ChemSusChem, 2015, 8(16): 2737-2744.

[本文引用: 2]

WATANABE T, TSUDA T, ANDO N, et al. An improved pre-lithiation of graphite anodes using through-holed cathode and anode electrodes in a laminated lithium ion battery[J]. Electrochimica Acta, 2019, 324: doi:10.1016/j.electacta.2019. 134848.

[本文引用: 2]

REZQITA A, KATHRIBAIL A R, KAHR J, et al. Analysis of degradation of Si/Carbon||LiNi0.5Mn0.3Co0.2O2 Full cells: Effect of prelithiation[J]. Journal of the Electrochemical Society, 2019, 166(3): A5483-A5488.

[本文引用: 1]

LIU N, HU L B, MCDOWELL M T, et al. Prelithiated silicon nanowires as an anode for lithium ion batteries[J]. ACS Nano, 2011, 5(8): 6487-6493.

[本文引用: 6]

BÄRMANN P, DIEHL M, GÖBEL L, et al. Impact of the silicon particle size on the pre-lithiation behavior of silicon/carbon composite materials for lithium ion batteries[J]. Journal of Power Sources, 2020, 464: doi:10.1016/j.jpowsour.2020.228224.

[本文引用: 3]

MENG Q H, LI G, YUE J P, et al. High-performance lithiated SiOx anode obtained by a controllable and efficient prelithiation strategy[J]. ACS Applied Materials & Interfaces, 2019, 11(35): 32062-32068.

[本文引用: 4]

SHELLIKERI A, WATSON V, ADAMS D, et al. Investigation of pre-lithiation in graphite and hard-carbon anodes using different lithium source structures[J]. Journal of the Electrochemical Society, 2017, 164(14): A3914-A3924.

[本文引用: 2]

WAN Y X, WANG L J, CHEN Y J, et al. A high-performance tin dioxide@carbon anode with a super high initial coulombic efficiency via a primary cell prelithiation process[J]. Journal of Alloys and Compounds, 2018, 740: 830-835.

[本文引用: 2]

YERSAK T A, SON S B, CHO J S, et al. An all-solid-state Li-ion battery with a pre-lithiated Si-Ti-Ni alloy anode[J]. Journal of the Electrochemical Society, 2013, 160(9): A1497-A1501.

[本文引用: 1]

HUANG S Z, ZHANG L, LIU L F, et al. Rationally engineered amorphous TiOx/Si/TiOx nanomembrane as an anode material for high energy lithium ion battery[J]. Energy Storage Materials, 2018, 12: 23-29.

[本文引用: 2]

WU W, WANG M, WANG J, et al. Green design of Si/SiO2/C composites as high-performance anodes for lithium-ion batteries[J]. ACS Applied Energy Materials, 2020, 3(4): 3884-3892.

[本文引用: 2]

RYU J, KANG J, KIM H, et al. Electrolyte-mediated nanograin intermetallic formation enables superionic conduction and electrode stability in rechargeable batteries[J]. Energy Storage Materials, 2020, 33: 164-172.

[本文引用: 1]

HASSOUN J, KIM J, LEE D J, et al. A contribution to the progress of high energy batteries: A metal-free, lithium-ion, silicon-sulfur battery[J]. Journal of Power Sources, 2012, 202: 308-313.

[本文引用: 1]

REN Y X, ZENG L, ZHAO C, et al. A safe and efficient lithiated silicon-sulfur battery enabled by a bi-functional composite interlayer[J]. Energy Storage Materials, 2020, 25: 217-223.

KIM K H, SHON J, JEONG H, et al. Improving the cyclability of silicon anodes for lithium-ion batteries using a simple pre-lithiation method[J]. Journal of Power Sources, 2020, 459: doi:10.1016/j.jpowsour.2020.228066.

[本文引用: 1]

SONG B F, DHANABALAN A, BISWAL S L. Evaluating the capacity ratio and prelithiation strategies for extending cyclability in porous silicon composite anodes and lithium iron phosphate cathodes for high capacity lithium-ion batteries[J]. Journal of Energy Storage, 2020, 28: doi:10.1016/j.est.2020.101268.

[本文引用: 1]

YANG Y X, NI C L, GAO M X, et al. Dispersion-strengthened microparticle silicon composite with high anti-pulverization capability for Li-ion batteries[J]. Energy Storage Materials, 2018, 14: 279-288.

[本文引用: 3]

WANG G W, LI F F, LIU D, et al. Chemical prelithiation of negative electrodes in ambient air for advanced lithium-ion batteries[J]. ACS Applied Materials & Interfaces, 2019, 11(9): 8699-8703.

[本文引用: 5]

SHEN Y F, ZHANG J M, PU Y F, et al. Effective chemical prelithiation strategy for building a silicon/sulfur Li-ion battery[J]. ACS Energy Letters, 2019, 4(7): 1717-1724.

[本文引用: 5]

MA R J, LIU Y F, HE Y P, et al. Chemical preinsertion of lithium: An approach to improve the intrinsic capacity retention of bulk Si anodes for Li-ion batteries[J]. The Journal of Physical Chemistry Letters, 2012, 3(23): 3555-3558.

[本文引用: 2]

YANG Y X, QU X L, ZHANG L C, et al. Reaction-ball-milling-driven surface coating strategy to suppress pulverization of microparticle Si anodes[J]. ACS Applied Materials & Interfaces, 2018, 10(24): 20591-20598.

PANG Y P, WANG X T, SHI X X, et al. Solid-state prelithiation enables high-performance Li-Al-H anode for solid-state batteries[J]. Advanced Energy Materials, 2020, 10(12): doi: 10.1002/aenm. 201902795.

ALABOINA P K, CHO J S, UDDIN M J, et al. Mechanically prelithiated silicon nano alloy as highly engineered anode material[J]. Electrochimica Acta, 2017, 258: 623-630.

[本文引用: 1]

SCOTT M G, WHITEHEAD A H, OWEN J R. Chemical formation of a solid electrolyte interface on the carbon electrode of a Li-ion cell[J]. Journal of the Electrochemical Society, 1998, 145(5): 1506-1510.

[本文引用: 1]

WANG G W, LI F F, LIU D, et al. High performance lithium-ion and lithium-sulfur batteries using prelithiated phosphorus/carbon composite anode[J]. Energy Storage Materials, 2020, 24: 147-152.

[本文引用: 2]

JANG J, KANG I, CHOI J, et al. Molecularly tailored lithium-arene complex enables chemical prelithiation of high-capacity lithium-ion battery anodes[J]. Angewandte Chemie International Edition, 2020, 59(34): 14473-14480.

[本文引用: 4]

SHEN Y F, SHEN X H, YANG M, et al. Achieving desirable initial coulombic efficiencies and full capacity utilization of Li-ion batteries by chemical prelithiation of graphite anode[J]. Advanced Functional Materials, 2021, 31(24): doi:10.1002/adfm.202101181.

[本文引用: 3]

CHOI J, JEONG H, JANG J, et al. Weakly solvating solution enables chemical prelithiation of graphite-SiOx anodes for high-energy Li-ion batteries[J]. Journal of the American Chemical Society, 2021, 143(24): 9169-9176.

[本文引用: 4]

XU H, LI S, ZHANG C, et al. Roll-to-roll prelithiation of Sn foil anode suppresses gassing and enables stable full-cell cycling of lithium ion batteries[J]. Energy & Environmental Science, 2019, 12(10): 2991-3000.

[本文引用: 4]

YAN M Y, LI G, ZHANG J, et al. Enabling SiOx/C anode with high initial coulombic efficiency through a chemical pre-lithiation strategy for high-energy-density lithium-ion batteries[J]. ACS Applied Materials & Interfaces, 2020, 12(24): 27202-27209.

[本文引用: 2]

SHEN Y F, QIAN J F, YANG H X, et al. Chemically prelithiated hard-carbon anode for high power and high capacity Li-ion batteries[J]. Small, 2020, 16(7): doi:10.1002/smll.201907602.

TABUCHI T, YASUDA H, YAMACHI M. Li-doping process for LixSiO-negative active material synthesized by chemical method for lithium-ion cells[J]. Journal of Power Sources, 2005, 146(1/2): 507-509.

LI F F, WANG G W, ZHENG D, et al. Controlled prelithiation of SnO2/C nanocomposite anodes for building full lithium-ion batteries[J]. ACS Applied Materials & Interfaces, 2020, 12(17): 19423-19430.

[本文引用: 1]

HUANG Y M, LIU C, WEI F Y, et al. Chemical prelithiation of Al for use as an ambient air compatible and polysulfide resistant anode for Li-ion/S batteries[J]. Journal of Materials Chemistry A, 2020, 8(36): 18715-18720.

[本文引用: 1]

陆浩, 李金熠, 刘柏男, 等. 锂离子电池纳米硅碳负极材料研发进展[J]. 储能科学与技术, 2017, 6(5): 864-870.

[本文引用: 1]

LU H, LI J Y, LIU B N, et al. Research and technology progress of nano-Si/C anode materials for lithium ion batteries[J]. Energy Storage Science and Technology, 2017, 6(5): 864-870.

[本文引用: 1]

YU Y, LI S, FAN H M, et al. Optimal annealing of Al foil anode for prelithiation and full-cell cycling in Li-ion battery: The role of grain boundaries in lithiation/delithiation ductility[J]. Nano Energy, 2020, 67: doi:10.1016/j.nanoen.2019.104274.

[本文引用: 1]

FAN H M, LI S, YU Y, et al. Air-stable LixAl foil as free-standing electrode with improved electrochemical ductility by shot-peening treatment[J]. Advanced Functional Materials, 2021, 31(29): doi:10.1002/adfm.202100978.

XU H, LI S, CHEN X L, et al. Surpassing lithium metal rechargeable batteries with self-supporting Li-Sn-Sb foil anode[J]. Nano Energy, 2020, 74: doi:10.1016/j.nanoen.2020.104815.

XU H, LI S, CHEN X L, et al. Sn-alloy foil electrode with mechanical prelithiation: Full-cell performance up to 200 cycles[J]. Advanced Energy Materials, 2019, 9(42): doi: 10.1002/aenm. 201902150.

FAN H M, CHEN B, LI S, et al. Nanocrystalline Li-Al-Mn-Si foil as reversible Li host: Electronic percolation and electrochemical cycling stability[J]. Nano Letters, 2020, 20(2): 896-904.

[本文引用: 1]

FORNEY M W, GANTER M J, STAUB J W, et al. Prelithiation of silicon-carbon nanotube anodes for lithium ion batteries by stabilized lithium metal powder (SLMP)[J]. Nano Letters, 2013, 13(9): 4158-4163.

[本文引用: 6]

CHEN H, YANG Y, BOYLE D T, et al. Free-standing ultrathin lithium metal-graphene oxide host foils with controllable thickness for lithium batteries[J]. Nature Energy, 2021, 6: 790-798.

[本文引用: 4]

CHENG X B, ZHANG R, ZHAO C Z, et al. Toward safe lithium metal anode in rechargeable batteries: A review[J]. Chemical Reviews, 2017, 117(15): 10403-10473.

[本文引用: 1]

LI Y X, FITCH B. Effective enhancement of lithium-ion battery performance using SLMP[J]. Electrochemistry Communications, 2011, 13(7): 664-667.

[本文引用: 1]

XIANG B, WANG L, LIU G, et al. Electromechanical probing of Li/Li2CO3 Core/shell particles in a TEM[J]. Journal of the Electrochemical Society, 2013, 160(3): A415-A419.

[本文引用: 1]

HEINE J, RODEHORST U, QI X, et al. Using polyisobutylene as a non-fluorinated binder for coated lithium powder (CLiP) electrodes[J]. Electrochimica Acta, 2014, 138: 288-293.

[本文引用: 2]

Coated lithium powder (CLiP) electrodes for lithium-metal batteries[J]. Advanced Energy Materials, 2014, 4(5): doi:10.1002/aenm.201400406.

[本文引用: 1]

KANG T, WANG Y L, GUO F, et al. Self-assembled monolayer enables slurry-coating of Li anode[J]. ACS Central Science, 2019, 5(3): 468-476.

[本文引用: 1]

LI X M, LI Y S, TANG Y F, et al. Air stable lithium microspheres prelithiation reagents for Li-ion batteries synthesized via electroplating[J]. Journal of Power Sources, 2021, 496: doi: 10.1016/j.jpowsour.2021.229868.

[本文引用: 1]

HUANG B, HUANG T, WAN L Y, et al. Pre-lithiating SiO anodes for lithium-ion batteries by a simple, effective, and controllable strategy using stabilized lithium metal powder[J]. ACS Sustainable Chemistry & Engineering, 2021, 9(2): 648-657.

[本文引用: 1]

AI G, WANG Z H, ZHAO H, et al. Scalable process for application of stabilized lithium metal powder in Li-ion batteries[J]. Journal of Power Sources, 2016, 309: 33-41.

[本文引用: 1]

WANG L, FU Y B, BATTAGLIA V S, et al. SBR-PVDF based binder for the application of SLMP in graphite anodes[J]. RSC Advances, 2013, 3(35): 15022.

[本文引用: 1]

SEONG I W, YOON W Y. Electrochemical behavior of a silicon monoxide and Li-powder double layer anode cell[J]. Journal of Power Sources, 2010, 195(18): 6143-6147.

[本文引用: 1]

CAO Z Y, XU P Y, ZHAI H W, et al. Ambient-air stable lithiated anode for rechargeable Li-ion batteries with high energy density[J]. Nano Letters, 2016, 16(11): 7235-7240.

[本文引用: 1]

ZHAO J, LU Z, LIU N, et al. Dry-air-stable lithium silicide–lithium oxide core-shell nanoparticles as high-capacity prelithiation reagents[J]. Nature Communications, 2014, 5: 5088.

[本文引用: 4]

ZHAO J, LU Z D, WANG H T, et al. Artificial solid electrolyte interphase-protected LixSi nanoparticles: An efficient and stable prelithiation reagent for lithium-ion batteries[J]. Journal of the American Chemical Society, 2015, 137(26): 8372-8375.

[本文引用: 3]

ZHAO J, LEE H W, SUN J, et al. Metallurgically lithiated SiOx anode with high capacity and ambient air compatibility[J]. Proceedings of the National Academy of Sciences of the United States of America, 2016, 113(27): 7408-7413.

[本文引用: 3]

ZHAO J, SUN J, PEI A, et al. A general prelithiation approach for group IV elements and corresponding oxides[J]. Energy Storage Materials, 2018, 10: 275-281.

[本文引用: 3]

PARK K, YU B C, GOODENOUGH J B. Li3N as a cathode additive for high-energy-density lithium-ion batteries[J]. Advanced Energy Materials, 2016, 6(10): doi:10.1002/aenm.201502534.

[本文引用: 4]

SUN Y, LEE H W, SEH Z W, et al. High-capacity battery cathode prelithiation to offset initial lithium loss[J]. Nature Energy, 2016, 1: 15008.

[本文引用: 4]

LIU Z Z, MA S B, MU X, et al. A scalable cathode chemical prelithiation strategy for advanced silicon-based lithium ion full batteries[J]. ACS Applied Materials & Interfaces, 2021, 13(10): 11985-11994.

[本文引用: 4]

WANG X Y, LIU C, ZHANG S J, et al. Dual-functional cathodic prelithiation reagent of Li3P in lithium-ion battery for compensating initial capacity loss and enhancing safety[J]. ACS Applied Energy Materials, 2021, 4(5): 5246-5254.

[本文引用: 4]

SUN Y M, LI Y B, SUN J, et al. Stabilized Li3N for efficient battery cathode prelithiation[J]. Energy Storage Materials, 2017, 6: 119-124.

[本文引用: 1]

YANG S Y, YUE X Y, XIA H Y, et al. Battery prelithiation enabled by lithium fixation on cathode[J]. Journal of Power Sources, 2020, 480: doi:10.1016/j.jpowsour.2020.229109.

[本文引用: 1]

ZHAN Y J, YU H L, BEN L B, et al. Application of Li2S to compensate for loss of active lithium in a Si-C anode[J]. Journal of Materials Chemistry A, 2018, 6(15): 6206-6211.

[本文引用: 1]

ZHAN Y J, YU H L, BEN L B, et al. Using Li2S to compensate for the loss of active lithium in Li-ion batteries[J]. Electrochimica Acta, 2017, 255: 212-219.

[本文引用: 1]

BIE Y T, YANG J, WANG J L, et al. Li2O2 as a cathode additive for the initial anode irreversibility compensation in lithium-ion batteries[J]. Chemical Communications (Cambridge, England), 2017, 53(59): 8324-8327.

[本文引用: 1]

SUN Y M, LEE H W, ZHENG G Y, et al. In situ chemical synthesis of lithium fluoride/metal nanocomposite for high capacity prelithiation of cathodes[J]. Nano Letters, 2016, 16(2): 1497-1501.

[本文引用: 1]

SUN Y M, LEE H W, SEH Z W, et al. Lithium sulfide/metal nanocomposite as a high-capacity cathode prelithiation material[J]. Advanced Energy Materials, 2016, 6(12): doi:10.1002/aenm. 201600154.

RAO Z X, WU J Y, HE B, et al. A prelithiation separator for compensating the initial capacity loss of lithium-ion batteries[J]. ACS Applied Materials & Interfaces, 2021, 13(32): 38194-38201.

[本文引用: 1]

DU J M, WANG W Y, ENG A Y S, et al. Metal/LiF/Li2O nanocomposite for battery cathode prelithiation: Trade-off between capacity and stability[J]. Nano Letters, 2020, 20(1): 546-552.

[本文引用: 2]

ABOUIMRANE A, CUI Y J, CHEN Z H, et al. Enabling high energy density Li-ion batteries through Li2O activation[J]. Nano Energy, 2016, 27: 196-201.

[本文引用: 1]

ZOU K Y, SONG Z R, GAO X, et al. Molecularly compensated pre-metallation strategy for metal-ion batteries and capacitors[J]. Angewandte Chemie International Edition, 2021, 60(31): 17070-17079.

[本文引用: 3]

FAN L J, TANG D C, WANG D Y, et al. LiCoO2-catalyzed electrochemical oxidation of Li2CO3[J]. Nano Research, 2016, 9(12): 3903-3913.

[本文引用: 3]

SOLCHENBACH S, WETJEN M, PRITZL D, et al. Lithium oxalate as capacity and cycle-life enhancer in LNMO/graphite and LNMO/SiG full cells[J]. Journal of the Electrochemical Society, 2018, 165(3): A512-A524.

[本文引用: 3]

SHANMUKARAJ D, GRUGEON S, LARUELLE S, et al. Sacrificial salts: Compensating the initial charge irreversibility in lithium batteries[J]. Electrochemistry Communications, 2010, 12(10): 1344-1347.

[本文引用: 2]

WANG R, YU X Q, BAI J M, et al. Electrochemical decomposition of Li2CO3 in NiO-Li2CO3 nanocomposite thin film and powder electrodes[J]. Journal of Power Sources, 2012, 218: 113-118.

[本文引用: 2]

NOH M, CHO J. Role of Li6CoO4Cathode additive in Li-ion cells containing low coulombic efficiency anode material[J]. Journal of the Electrochemical Society, 2012, 159(8): A1329-A1334.

[本文引用: 1]

PARK H, YOON T, KIM Y U, et al. Li2NiO2 as a sacrificing positive additive for lithium-ion batteries[J]. Electrochimica Acta, 2013, 108: 591-595.

[本文引用: 1]

PARK K S, IM D, BENAYAD A, et al. LiFeO2-incorporated Li2MoO3 as a cathode additive for lithium-ion battery safety[J]. Chemistry of Materials, 2012, 24(14): 2673-2683.

[本文引用: 1]

JEŻOWSKI P, FIC K, CROSNIER O, et al. Lithium rhenium(vii) oxide as a novel material for graphite pre-lithiation in high performance lithium-ion capacitors[J]. Journal of Materials Chemistry A, 2016, 4(32): 12609-12615.

[本文引用: 1]

VITINS G, RAEKELBOOM E A, WELLER M T, et al. Li2CuO2 as an additive for capacity enhancement of lithium ion cells[J]. Journal of Power Sources, 2003, 119/120/121: 938-942.

[本文引用: 1]

ZHANG L H, DOSE W M, VU A D, et al. Mitigating the initial capacity loss and improving the cycling stability of silicon monoxide using Li5FeO4[J]. Journal of Power Sources, 2018, 400: 549-555.

[本文引用: 1]

DOSE W M, VILLA C, HU X B, et al. Beneficial effect of Li5FeO4 lithium source for Li-ion batteries with a layered NMC cathode and Si anode[J]. Journal of the Electrochemical Society, 2020, 167(16): 160543.

[本文引用: 2]

ARAVINDAN V, NAN S, KEPPELER M, et al. Pre-lithiated LixMn2O4: A new approach to mitigate the irreversible capacity loss in negative electrodes for Li-ion battery[J]. Electrochimica Acta, 2016, 208: 225-230.

[本文引用: 3]

DOSE W M, BLAUWKAMP J, PIERNAS-MUÑOZ M J, et al. Liquid ammonia chemical lithiation: An approach for high-energy and high-voltage Si-Graphite|Li1+ xNi0.5Mn1.5O4 Li-ion batteries[J]. ACS Applied Energy Materials, 2019, 2(7): 5019-5028.

[本文引用: 5]

LIU Y, YANG B C, DONG X L, et al. A simple prelithiation strategy to build a high-rate and long-life lithium-ion battery with improved low-temperature performance[J]. Angewandte Chemie International Edition, 2017, 56(52): 16606-16610.

[本文引用: 3]

YANG L Y, YANG K, ZHENG J X, et al. Harnessing the surface structure to enable high-performance cathode materials for lithium-ion batteries[J]. Chemical Society Reviews, 2020, 49(14): 4667-4680.

[本文引用: 1]

WANG R, QIAN G Y, LIU T C, et al. Tuning Li-enrichment in high-Ni layered oxide cathodes to optimize electrochemical performance for Li-ion battery[J]. Nano Energy, 2019, 62: 709-717.

TANG Z F, WANG S, LIAO J Y, et al. Facilitating lithium-ion diffusion in layered cathode materials by introducing Li+/Ni2+ antisite defects for high-rate Li-ion batteries[J]. Research (Washington, D C), 2019: doi: 10.34133/2019/2198906.

[本文引用: 1]

LIU X X, LIU T C, WANG R, et al. Prelithiated Li-enriched gradient interphase toward practical high-energy NMC-silicon full cell[J]. ACS Energy Letters, 2021, 6(2): 320-328.

[本文引用: 2]

LIU X X, TAN Y C, WANG W Y, et al. Conformal prelithiation nanoshell on LiCoO2 enabling high-energy lithium-ion batteries[J]. Nano Letters, 2020, 20(6): 4558-4565.

[本文引用: 2]

SONG Z H, FENG K, ZHANG H Z, et al. “Giving comes before receiving”: High performance wide temperature range Li-ion battery with Li5V2(PO4)3 as both cathode material and extra Li donor[J]. Nano Energy, 2019, 66: doi:10.1016/j.nanoen.2019. 104175.

[本文引用: 1]

BETZ J, NOWAK L, WINTER M, et al. An approach for pre-lithiation of Li1+ xNi0.5Mn1.5O4 cathodes mitigating active lithium loss[J]. Journal of the Electrochemical Society, 2019, 166(15): A3531-A3538.

[本文引用: 1]

PERAMUNAGE D, ABRAHAM K M. Preparation and electrochemical characterization of overlithiated spinel LiMn2O4[J]. Journal of the Electrochemical Society, 1998, 145(4): 1131-1136.

[本文引用: 1]

TARASCON J M, GUYOMARD D. Li metal-free rechargeable batteries based on Li1+ xMn2O4 cathodes (0 ≤x≤ 1) and carbon anodes[J]. Journal of the Electrochemical Society, 1991, 138(10): 2864-2868.

[本文引用: 1]

MANCINI M, AXMANN P, GABRIELLI G, et al. A high-voltage and high-capacity Li1+ xNi0.5Mn1.5O4 cathode material: From synthesis to full lithium-ion cells[J]. ChemSusChem, 2016, 9(14): 1843-1849.

[本文引用: 1]

MOORHEAD-ROSENBERG Z, ALLCORN E, MANTHIRAM A. In situ mitigation of first-cycle anode irreversibility in a new spinel/FeSb lithium-ion cell enabled via a microwave-assisted chemical lithiation process[J]. Chemistry of Materials, 2014, 26(20): 5905-5913.

[本文引用: 1]

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