Jiao Yu, Chen Wei, Lei Tianyu, Dai Liping, Chen Bo, Wu Chunyang, Xiong Jie
School of Applied and Chemical Engineering, Xichang College, Xichang, 615053, China.
State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China.
Nanoscale Res Lett. 2017 Dec;12(1):195. doi: 10.1186/s11671-017-1948-5. Epub 2017 Mar 16.
High energy density, low cost and environmental friendliness are the advantages of lithium-sulfur (Li-S) battery which is regarded as a promising device for electrochemical energy storage systems. As one of the important ingredients in Li-S battery, the binder greatly affects the battery performance. However, the conventional binder has some drawbacks such as poor capability of absorbing hydrophilic lithium polysulfides, resulting in severe capacity decay. In this work, we reported a multi-functional polar binder (AHP) by polymerization of hexamethylene diisocyanate (HDI) with ethylenediamine (EDA) bearing a large amount of amino groups, which were successfully used in electrode preparation with commercial sulfur powder cathodes. The abundant amide groups of the binder endow the cathode with multidimensional chemical bonding interaction with sulfur species within the cathode to inhibit the shuttling effect of polysulfides, while the suitable ductility to buffer volume change. Utilizing these advantageous features, composite C/S cathodes based the binder displayed excellent capacity retention at 0.5 C, 1 C, 1.5 C, and 3 C over 200 cycles. Accompany with commercial binder, AHP may act as an alternative feedstock to open a promising approach for sulfur cathodes in rechargeable lithium battery to achieve commercial application.
高能量密度、低成本和环境友好性是锂硫（Li-S）电池的优点，该电池被视为电化学储能系统中有前景的装置。作为Li-S电池的重要成分之一，粘结剂对电池性能有很大影响。然而，传统粘结剂存在一些缺点，如吸收亲水性多硫化锂的能力较差，导致严重的容量衰减。在这项工作中，我们通过六亚甲基二异氰酸酯（HDI）与带有大量氨基的乙二胺（EDA）聚合，报道了一种多功能极性粘结剂（AHP），其成功用于商业硫粉阴极的电极制备。粘结剂丰富的酰胺基团使阴极与阴极内的硫物种具有多维化学键相互作用，以抑制多硫化物的穿梭效应，同时具有合适的延展性来缓冲体积变化。利用这些有利特性，基于该粘结剂的复合C/S阴极在0.5 C、1 C、1.5 C和3 C下200次循环中表现出优异的容量保持率。与商业粘结剂一起，AHP可作为一种替代原料，为可充电锂电池中的硫阴极开辟一条有前景的途径，以实现商业应用。
