储能科学与技术 ›› 2020, Vol. 9 ›› Issue (2): 385-391.doi: 10.19799/j.cnki.2095-4239.2020.0006

• 庆祝陈立泉院士八十寿辰专刊 • 上一篇    下一篇

探究锡在钠离子电池层状铬基正极材料中的作用

卞静静(), 褚世勇, 奚凯颖, 郭少华(), 周豪慎   

  1. 南京大学现代工程与应用科学学院，固体微结构物理国家重点实验室，人工微结构科学与技术协同创新中心，江苏省功能材料设计原理与应用技术重点实验室，江苏 南京 210093
  • 收稿日期:2020-01-05 修回日期:2020-02-06 出版日期:2020-03-05 发布日期:2020-03-15
  • 通讯作者: 郭少华 E-mail:151190003@mail.nju.edu.cn;shguo@nju.edu.cn
  • 作者简介:卞静静（1997—），女，硕士研究生，研究方向为钠离子电池电极材料，E-mail：151190003@mail.nju.edu.cn；|周豪慎教授，研究方向为能源材料、气体传感器、太阳能电池、超级电容器、二次电池、锂离子电池、锂空气电池及下一代储能器件等的研究和开发，E-mail：hszhou@nju.edu.cn。
  • 基金资助:
    国家重点研发计划(2018YFB0104302);国家自然科学基金(51802149);江苏省自然科学基金(BK20170630┫项目)

Role of Sn doping in layered chromium-based cathode materials for sodium-ion batteries

BIAN Jingjing(), CHU Shiyong, XI Kaiying, GUO Shaohua(), ZHOU Haoshen   

  1. College of Engineering and Applied Sciences, National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210093, Jiangsu, China
  • Received:2020-01-05 Revised:2020-02-06 Online:2020-03-05 Published:2020-03-15
  • Contact: Shaohua GUO E-mail:151190003@mail.nju.edu.cn;shguo@nju.edu.cn

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摘要：

当今社会，人类对电子产品越来越依赖，因此，对电化学储能这项技术的需求也日益剧增。迄今，广泛应用的锂电池具有高的能量密度等优点，但是它的发展受限于越来越少的锂储量。钠离子电池的潜在应用有望解决这一问题，钠在地球中的储量丰富、分布广泛、价格低廉，并且与锂有相似的物理化学性质，可以作为锂的替代材料应用于电池中。在层状铬酸钠（NaCrO2）基础上发展的正极材料具有原料丰富、合成条件简单、成分可控等优点。但充电到高电压后，铬离子会从过渡金属层迁移到钠层中，铬酸钠的结构会发生不可逆结构转变，最终导致电池容量衰减。本研究通过向铬酸钠中掺入离子半径较大的锡（Sn）生成一种新的层状材料Na0.7Cr0.85Sn0.15O2。对材料进行X射线衍射分析和扫描电子显微镜表征，以及一系列的电化学测试和反应动力学测试，结果证明掺杂后的材料有平滑的电压曲线和稳定的晶体结构，并且缓解了容量的严重衰减，提高了循环稳定性。新型层状材料还具有更小的阻抗和极化，动力学性能更优异。此外，掺杂后的材料的空气稳定性也有很大提高。这种新型的层状铬基氧化物正极材料有望为钠离子电池正极材料的发展提供一个新的选择。

关键词: 钠离子电池, 层状正极, 钠铬氧化物, 锡掺杂

Abstract:

The demand for electrochemical energy storage technology has significantly increased. Currently, the large-scale application of lithium-ion batteries can be attributed to their advantages such as high energy density and large power density; however, limited lithium resources restrict the further development of lithium-ion batteries. The potential applications of sodium-ion batteries are expected to solve this problem. Sodium is abundant, widely distributed, cheap, and has physical and chemical properties similar to those of lithium. Sodium can be used as a substitute for lithium in batteries. A Cr-based layered cathode material has the following advantages: abundant raw materials, easy synthesis methods, and controllable composition. However, when the Cr-based layered cathode material is charged to a relatively high voltage, Cr ions migrate from the transition metal layer to the sodium layer, and the structure of sodium chromate will undergo an irreversible structural transformation, which diminishes the capacity. In this study, a new layered material, Na0.7Cr0.85Sn0.15O2, was fabricated by doping Sn, which has a large ionic radius, into sodium chromate. The structure and electrochemical performance of the materials were systematically investigated. The results show that the doped material has a smooth voltage curve and a stable crystal structure. In addition, doping alleviates the serious attenuation of capacity and improves cycle stability. This new layered chromium-based oxide cathode material is expected to provide a new option for the development of cathode materials for sodium-ion batteries.

Key words: sodium-ion batteries, layered cathode, Cr-based oxide, Sn doping

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