[1]员紫梦,刘单单,黄佳佳.黏结剂对钾硫电池正极材料性能的影响研究[J].郑州大学学报(工学版),2022,43(6):70-76.
 YUN Z M,LIU D D,HUANG J J.Effect of Binders on the Performance of SPAN Cathode for Potassium-sulfur Batteries[J].Journal of Zhengzhou University (Engineering Science),2022,43(6):70-76.
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黏结剂对钾硫电池正极材料性能的影响研究()
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《郑州大学学报(工学版)》[ISSN:1671-6833/CN:41-1339/T]

卷:
43
期数:
2022年6期
页码:
70-76
栏目:
出版日期:
2022-09-02

文章信息/Info

Title:
Effect of Binders on the Performance of SPAN Cathode for Potassium-sulfur Batteries
作者:
员紫梦 刘单单 黄佳佳
Author(s):
YUN Z M LIU D DHUANG J J
文献标志码:
A
摘要:
针对钾硫( K-S)电池中硫化聚丙烯腈( SPAN)正极在循环过程中因结构不稳定易发生容量衰减问题,以黏结剂为研究对象,比较了羧甲基纤维素钠( CMC) 和聚偏二氟乙烯( PVDF) 黏结剂对 SPAN 正极电化学性能的影响,并进一步通过动力学测试和电极形貌微观测试探明黏结剂结构对电池性能的影 响机理。 倍率性 能测 试结果 表明:使用 CMC 黏 结剂制备的 SPAN 电极在 0. 1C、0. 2C、0. 5C、1C、2C、3C 倍 率下分别具有 1 256、 1 16 1、1 058、946、716、538 mAh / g 的放电比容量,之后再以 0. 1C 倍率充放电所得放电比容量仍保持为 1 253 mAh / g,明显优于 PVDF 黏结剂制备的 SPAN 电极的倍率性能。 此外,循环性 能 测试结果表明:使用 CMC 黏结剂制备的 SPAN 电极在 0. 5C 电流密度下经过 100 次循环后仍具有 822 mAh / g 的放电比容量,容量保持率高达 75. 6%,明显优于 PVDF 黏结剂制备的 SPAN 电极的循环性能。 机理测试结果表明:CMC 黏结剂性能优异的原因在于其结构中大量的含氧活性官能团,一方面可 以与活性物质颗粒之间形成较强的化学相互作用,显著提高黏附强度,从而能够承受循环过程中 SPAN正极巨大的体积变化,维持电极内部导电网络的稳定,防止电极结构坍塌,提高电池的循环稳定性;另一 方面,— COONa 可以提高 电极的钾 离子扩散系数,促进 钾离子传输,改 善电池的倍率性能。
Abstract:
Owing to the large radius of potassium ions, the SPAN cathode suffers large volume change during the cycling process, which causes structure collapse and serious capacity fade. Herein, the effects of sodium carboxymethyl cellulose (CMC) and polyvinylidene fluoride PVDF) on the electrochemical performance of SPAN cathode in K-S battery were investigated, and the reason of CMC binder improving the electrochemical performance of SPAN cathode was further explored by kinetic test and SEM test. The rate performance test results showed that the SPAN electrode prepared by CMC binder displayed capacity of 1 256, 1 161, 1 058, 946, 716, 538 mAh/g at 0. 1C, 0. 2C, 0. 5C, 1C, 2C, 3C. And the capacity remained 1 253 mAh/g when the current density returns to 0. 1C, which was far better than the rate performance of SPAN electrode pre- pared by PVDF binder. Besides, the cycle performance test results showed that the SPAN electrode prepared by CMC binder could deliver a high reversible capacity of 822 mAh/g after 100 cycles at 0.5C, corresponding to a high capacity retention of 75. 6%. The mechanism test results showed that benefit from the abundant oxy- gen-containing active functional groups in the CMC structure which could not only strengthen chemical interac- tions with active materials, alleviate the volume change of SPAN cathode during the charge/discharge process, but also accelerate the transport of potassium ion. The SPAN electrode prepared by CMC binder demonstrated a high rate performance and cycle performance compared to the case of PVDF binder. The finding of this study provided an effective strategy to restrain the volume expansion of potassium-sulfur batteries, to maintain the stability of the conductive network inside the electrode, thereby to improve the rate performance and cycle sta- bility.
更新日期/Last Update: 2022-10-03