Investigation on xanthan gum as novel water soluble binder for LiFePO4 cathode in lithium-ion batteries
Investigation on xanthan gum as novel water soluble binder for LiFePO4 cathode in lithium-ion batteries
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黄原胶作为锂离子电池LiFePO4正极新型水溶性粘合剂的研究
DOI：
10.1016/j.jallcom.2017.04.238
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发表时间：
2017-08-15
影响因子：
6.2
通讯作者：
Zhang, Lingzhi
中科院分区：
文献类型：
--
作者：
He, Jiarong;Zhong, Haoxiang;Zhang, Lingzhi
系统地研究了黄原胶(XG)作为锂离子电池正极材料LiFePO4(LFP)的水溶性粘结剂。XG粘结剂具有良好的热稳定性和丰富的羧基和羟基等官能团，其粘接强度为0.085 N cm(-1)，高于羧甲基纤维素钠(0.050 N cm-1)，但逊于聚偏二氟乙烯(PVDF，0.170 N cm-1)。流变学测试表明，XG粘结剂制备的LFP浆料的粘度高于PVDF，有利于LFP和炭黑粒子的分散。研究了LFP-XG电极的电化学性能，并与水相CMC和常规PVDF粘结剂的性能进行了比较。LFP-XG表现出比PVDF更好的循环稳定性和倍率性能，与CMC相当，CMC在5℃时保持了55.3%的C/5容量，而PVDF和CMC的容量分别为34.8%和57.8%。循环伏安(CV)测试表明，LFP-XG的氧化还原极化比PVDF更小，锂扩散速度更快，而电化学阻抗谱(EIS)测试表明其比PVDF更有利的电化学动力学，与CMC相似，因此具有更好的倍率性能。扫描电子显微镜(SEM)表明，LFP-XG在循环前与XG相比，LFP和导电炭黑颗粒分布更均匀，100次循环后保持结构完整性比PVDF更好。此外，观察到LFP-XG具有DQ/DV分布支持的高离子导电性。(C)2017爱思唯尔B.V.保留所有权利。
Xanthan Gum (XG) is systematically investigated and employed as water soluble binder for LiFePO4 (LFP) cathode in Li-ion batteries. XG binder exhibits good thermal stability and processes abundant functional groups such as carboxyl and hydroxyl, displaying a better adhesion strength of 0.085 N cm(-1) than sodium carboxymethyl cellulose (CMC, 0.050 N cm(-1)), but inferior to polyvinylidene difluoride (PVDF, 0.170 N cm(-1)). The Rheology test reveals that the viscosity of LFP slurry prepared with XG binder is higher than that of PVDF, resulting in a better dispersion of LFP and carbon black particles. The electrochemical performances of LFP-XG electrode are investigated and compared with those of aqueous CMC and conventional PVDF binder. LFP-XG displays better cycle stability and rate performance than PVDF, comparable to CMC, which retains 55.3% capacity of C/5 at 5 C as compared to PVDF (34.8%) and CMC (57.8%). Cyclic voltammetry (CV) shows that LFP-XG has smaller redox polarization and faster lithium diffusion rate than PVDF while electrochemical impedance spectroscopy (EIS) measurement at specified intervals reveals its more favorable electrochemical kinetics than that with PVDF, similar to CMC, thus better rate capability. Scanning electron microscopy (SEM) displays that LFP-XG has a more homogenous distribution of LFP and conductive carbon black particles with XG before cycling and better maintains its structure integrity after 100 cycles than that of PVDF. Furthermore, LFP-XG is observed to process a high ionic conductivity supported by dQ/dV profiles. (C) 2017 Elsevier B.V. All rights reserved.