Water-based dual-network conductive polymer binders for high-performance Li–S batteries
Water-based dual-network conductive polymer binders for high-performance Li–S batteries
复制标题
DOI：
10.1016/j.electacta.2021.137822
复制
发表时间：
2021-03
影响因子：
6.6
通讯作者：
Hui Wang;Yinyan Wang;Guangzhao Zhang;Zhuohong Yang;Yukun Chen;Yonghong Deng;Yu Yang;Chaoyang Wang-Cha
中科院分区：
文献类型：
--
作者：
Hui Wang;Yinyan Wang;Guangzhao Zhang;Zhuohong Yang;Yukun Chen;Yonghong Deng;Yu Yang;Chaoyang Wang-Cha
粘结剂是典型锂硫电池的重要组成部分。它对于保持电极结构的完整性，保证活性材料与导电剂之间的有效连接起着至关重要的作用。然而，现有的商用粘合剂对于商用Li-S电池的结构来说还不够有希望；在它们的结合强度、导电性和对可溶性多硫中间体的亲和力方面仍有改进的余地。本文报道了一种新型双网络导电（DNC）粘合剂的制备。该粘合剂由导电网络（由聚3,4-乙烯二氧噻吩（PEDOT）和聚苯乙烯磺酸盐（PSS）组成）和交联吸收网络（由磷酸化大豆分离蛋白（P-SPI）、聚乙烯氧化物（PEO）和植酸（PA）组成）组成，具有优异的导电性和多硫化物吸附能力。通过详细的性能分析和分子动力学模拟，研究了不同粘结剂组分的功能，得出了两种网络的最佳配方。值得注意的是，硫负载为~1.7 mg cm-2的DNC粘结剂Li-S电池具有优异的长期稳定性，在0.5 C下循环400次后，其保持容量为751.9 mAh g- 1，库仑效率为99.57%。在含硫量为~1.2 mg cm-2的情况下，在4℃下的倍率性能为692.4 mAh g−1。
Binder is an essential component in the typical Li-S batteries. It plays a critical role in maintaining the structural integrity of electrodes and ensuring the effective connection between active materials and conductive agents. However, the existing commercial binders are not promising enough for the commercial Li-S battery construction; there are still rooms for improvement in terms of their bonding strength, conductivity, and affinity to the soluble polysulfide intermediates. Herein, the fabrication of a novel dual-network conductive (DNC) binder is reported. This as-developed binder consists of a conductive network (composed of poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(styrenesulfonate) (PSS)), and a crosslinking absorbing network composed of phosphorylated soy protein isolate (P-SPI), polyethylene oxide (PEO), and phytic acid (PA), demonstrating an excellent conductivity and polysulfide adsorption capability. Functions of different binder components are also investigated via detailed properties analysis and molecular dynamics simulations, which manifests an optimum prescription of the two networks. Remarkably, the DNC binder-based Li-S batteries with a sulfur loading of ~1.7 mg cm-2possess an excellent long-term stability , which has a high retention capacity of 751.9 mAh g−1after 400 cycles at 0.5 C with a coulombic efficiency of 99.57%. A good rate performance of 692.4 mAh g−1at 4 C under a sulfur loading of ~1.2 mg cm-2is also achieved.