储能科学与技术 ›› 2023, Vol. 12 ›› Issue (4): 1051-1058.doi: 10.19799/j.cnki.2095-4239.2022.0751

• 储能材料与器件 • 上一篇    下一篇

碳还原法制备棒状硅基材料及其在锂浆料电池中的应用

阮晶晶1(), 刘福园1, 李珅珅1, 高桂红1, 刘艳侠1,2()   

  1. 1.郑州中科新兴产业技术研究院，河南省储能材料与过程重点实验室，河南 郑州 450003
    2.中国科学院过程工程研究所，离子液体清洁过程北京重点实验室，北京 100190
  • 收稿日期:2022-12-14 修回日期:2022-12-22 出版日期:2023-04-05 发布日期:2023-02-09
  • 通讯作者: 刘艳侠 E-mail:15702413613@163.com;yxliu@ipe.ac.cn
  • 作者简介:阮晶晶（1989—），女，硕士，工程师，研究方向为电池材料及锂系电池，E-mail：15702413613@163.com；
  • 基金资助:
    国家重点研发计划项目(2019YFA0705603);河南省重点研发计划项目(221111240100)

Preparation of rod-like silicon-based material by carbon reduction and its application in lithium slurry batteries

Jingjing RUAN1(), Fuyuan LIU1, Shenshen LI1, Guihong GAO1, Yanxia LIU1,2()   

  1. 1.Zhengzhou Institute of Emerging Industrial Technology, Henan Key Laboratory of Energy Storage Materials and Processes, Zhengzhou 450003, Henan, China
    2.Beijing Key Laboratory of Ionic Liquids Clean Process, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
  • Received:2022-12-14 Revised:2022-12-22 Online:2023-04-05 Published:2023-02-09
  • Contact: Yanxia LIU E-mail:15702413613@163.com;yxliu@ipe.ac.cn

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摘要：

以聚环氧乙烷-聚环氧丙烷-聚环氧乙烷三嵌段共聚物(P123)为结构导向剂，正硅酸乙酯(TEOS)为硅源，柠檬酸为碳源，采用水热法得到凝胶状二氧化硅/碳前驱体，采用旋转蒸发方式去除溶剂，通过高温热处理，得到棒状硅氧基碳负极活性材料，提高浆料体系无紧密束缚环境下硅碳材料的性能。借助X射线衍射(XRD)仪、无机元素分析(EA)仪、比表面积及孔隙度分析仪和扫描电子显微镜(SEM)对棒状硅基材料进行结构和形貌表征。结果表明，合成的棒状硅基材料首尾相连，形成莲藕链束，长度约为1～3 μm，直径约为200 nm，孔径为6.9 nm，比表面积为282 m2/g。与管长>5 μm，比表面积900 m2/g，直径1～2 nm的单壁碳纳米管导电剂在电解液体系中形成长程、短程互补的多级网络，加上大量介孔的存在，有利于保持浆料悬浮稳定性。用世伟洛克电池进行电化学性能测试，电化学测试结果表明首次放电比容量为1300 mAh/g，充电比容量为726 mAh/g，首效为55.8%，在0.05 C下，循环50次充电比容量从726 mAh/g变为557 mAh/g，比容量保持率为76.7%。本工作在用P123为结构导向剂制备二氧化硅的过程中，引入碳源，得到同时具有碳包覆和碳还原二氧化硅的硅基材料，避免使用镁热还原二氧化硅，再碳包覆带来的复杂工艺流程。

关键词: 锂浆料电池, 负极材料, 棒状硅基材料, 碳源

Abstract:

In this study, a gel-like silica/carbon precursor was obtained by the hydrothermal method, with PEO-PPO-PEO(P123) as the structure directing agent, tetraethyl orthosilicate (TEOS) as the silicon source, and citric acid as the carbon source. The solvent was removed by rotary evaporation. The rod-like carbon-coated silicon oxide-negative material was obtained through high-temperature heat treatment, which improved the performance of the silicon-carbon material in the slurry system without a tight binding environment. The structure and morphology of this material were characterized by X-ray diffraction, inorganic element analyzer, specific surface area and porosity analyzer, and scanning electron microscope. The rod-like silicon-based material was joined end to end to form a lotus chain bundle having a length of about 1～3 μm, diameter of about 200 nm, pore size of 6.9 nm, and specific surface area of 282 m2/g This material and a single-walled carbon nanotube conductive agent with tube length >5 μm, specific surface area of 900 m2/g, and diameter of 1～2 nm form a multistage network of long and short range complementary in the electrolyte system. In addition, the presence of a large number of mesoporous materials was conducive to maintaining the suspension stability of slurry. The electrochemical performance test of the Swagelok battery showed that the initial discharge capacity was 1300 mAh/g, charging capacity was 726 mAh/g, and the coulombic efficiency was 55.8%. At 0.05 C, the charging capacity changed from 726 mAh/g to 557 mAh/g after 50 cycles, and the specific capacity retention rate was 76.7%. This work directly introduced carbon sources in the process of preparing silica with P123 as the structure guide agent and obtained silica-based materials with both carbon coating and carbon-reducing silica at the same time. Thus, this process avoided the complex technological process caused by magnesium thermal reduction of silica and recarbon coating.

Key words: lithium slurry battery, anode material, rod-like silicon -based material, carbon source

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