Dong Haobo, Hu Xueying, He Guanjie
Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
Christopher Ingold Laboratory, Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
Nanoscale. 2022 Oct 13;14(39):14544-14551. doi: 10.1039/d2nr04140e.
A conventional aqueous electrolyte is a crucial component of zinc-ion batteries providing an ion conductive medium. However, the monofunction of a liquid electrolyte cannot bear any external load. With regard to applications in electric vehicles and stationary energy storage devices, complicated battery packing materials are required to improve the mechanical properties, resulting in reduced energy or power densities from the perspective of the entire device. In this work, an electrolyte suspension combining both fluid-like and solid-like performances was developed for rechargeable zinc-ion batteries. Cornstarch water suspension is utilized in the electrolyte design forming a shear-thickening electrolyte with impact resistance ability. The formed electrolyte becomes rigid at a high shear rate. In other words, under a sudden impact, a battery with this shear-thickening electrolyte could offer additional load bearing avoiding short-circuiting and improving safety. Although an additional functionality, namely impact resistance, was added to the electrolyte, the as-prepared electrolyte still performs with comparable electrochemical performances for which it exhibits a superior ionic conductivity of 3.9 × 10 S cm and Zn transference number. This electrolyte even suppresses side-effects on the zinc anode, exhibiting a lower voltage gap in the symmetric cell compared to the aqueous electrolyte. The integrated full cell also delivered a specific capacity of 255 mA h g with commercial MnO as the cathode at a current density of 0.1 A g.
传统的水性电解质是锌离子电池的关键组成部分，可提供离子传导介质。然而，液体电解质的单一功能无法承受任何外部负载。对于电动汽车和固定式储能设备中的应用而言，需要复杂的电池包装材料来提高机械性能，从整个设备的角度来看，这会导致能量或功率密度降低。在这项工作中，为可充电锌离子电池开发了一种兼具类流体和类固体性能的电解质悬浮液。在电解质设计中使用玉米淀粉水悬浮液，形成具有抗冲击能力的剪切增稠电解质。所形成的电解质在高剪切速率下会变硬。换句话说，在突然受到冲击时，配备这种剪切增稠电解质的电池可以提供额外的承重能力，避免短路并提高安全性。尽管在电解质中添加了额外的功能，即抗冲击性，但所制备的电解质仍具有可比的电化学性能，其表现出3.9×10 S cm的优异离子电导率和锌迁移数。这种电解质甚至抑制了对锌负极的副作用，与水性电解质相比，在对称电池中表现出更低的电压间隙。在以商业MnO作为正极、电流密度为0.1 A g的情况下，集成全电池还实现了255 mA h g的比容量。
