Mechanically Robust Tapioca Starch Composite Binder with Improved Ionic Conductivity for Sustainable Lithium-Ion Batteries
Mechanically Robust Tapioca Starch Composite Binder with Improved Ionic Conductivity for Sustainable Lithium-Ion Batteries
复制标题
DOI：
10.1021/acssuschemeng.0c02843
复制
发表时间：
2020-07-06
影响因子：
8.4
通讯作者：
Yan, Cheng
中科院分区：
文献类型：
--
作者：
Hapuarachchi, Sashini N. S.;Wasalathilake, Kimal;Yan, Cheng
尽管粘合剂的用量很少，但它们对锂离子电池的性能具有重要作用。除了粘合性能差外，传统的聚偏二氟乙烯粘合剂还引起许多环境和健康问题，因为其加工过程涉及有害的有机溶剂。在这项研究中，我们引入了一种用聚乙二醇（PEG）基团改性的水溶性环保木薯淀粉粘合剂，作为锂离子电池中硅阳极电极的新型粘合剂。实验和密度泛函理论模拟表明，淀粉中丰富的羟基提高了与硅纳米粒子的结合强度，并且集成的PEG基团促进了硅电极中锂离子的传输。纳米压痕和划痕测试证实，电极的机械性能得到显着改善。观察到优异的电化学性能，初始锂化容量为 3486 mA h g(-1)，第二次循环容量保持率高达 98%，证明了其作为廉价且可持续的锂离子电池粘合剂的潜力。
Binders have an important function in the performance of Li-ion batteries even though they are only used in small quantities. In addition to poor adhesion properties, the traditional polyvinylidene difluoride binder raises many environmental and health concerns because of their processing that involves hazardous organic solvents. In this study, we introduced a water-soluble, environmentally friendly tapioca starch binder modified with polyethylene glycol (PEG) groups as a novel binder for Si anode electrodes in Li-ion batteries. The experiments and density functional theory simulations indicate that abundant hydroxyl groups in the starch improve the binding strength with Si nanoparticles, and the integrated PEG groups facilitate Li-ion transfer in the Si electrode. The mechanical behavior of the electrode is significantly improved, as confirmed by nanoindentation and scratch tests. Excellent electrochemical performance is observed, with an initial lithiation capacity of 3486 mA h g(-1) and a noteworthy second cycle capacity retention of 98%, demonstrating its potential as a cheap and sustainable binder for Li-ion batteries.