Surface-Functionalized Separator for Stable and Reliable Lithium Metal Batteries: A Review

Metallic Li has caught the attention of researchers studying future anodes for next-generation batteries, owing to its attractive properties: high theoretical capacity, highly negative standard potential, and very low density. However, inevitable issues, such as inhomogeneous Li deposition/dissolution and poor Coulombic efficiency, hinder the pragmatic use of Li anodes for commercial rechargeable batteries. As one of viable strategies, the surface functionalization of polymer separators has recently drawn significant attention from industries and academics to tackle the inherent issues of metallic Li anodes. In this article, separator-coating materials are classified into five or six categories to give a general guideline for fabricating functional separators compatible with post-lithium-ion batteries. The overall research trends and outlook for surface-functionalized separators are reviewed

Electrically conductive metal oxide-Assisted multifunctional separator for highly stable Lithium-Metal batteries

Lithium (Li) metal anodes have received intensive attention owing to its high specific capacity and low redox potential. However, chronic issues related to dendritic Li growth have hindered the pragmatic use of Li-metal batteries (LMBs). As one of feasible approaches, depositing a functional material on the separator is an efficient strategy for improving the electrochemical stability of LMBs. In this paper, we report a functionalized separator, comprising a nitrided niobium dioxide (named as n-NbO2) and a polypropylene (PP) separator. It is identified that niobium oxide interact with metallic Li, resulting in redistributing the localized Li ion. The n-NbO2-coated separator with enhanced electrical conductivity promotes Li plating/stripping process, reinforcing the Li ion redistribution effect. Due to these properties, Li-Cu cells with the n-NbO2-coated separator show the most outstanding cycle stability with high Coulombic efficiency (CE) over 200 cycles

A Strategic Approach to Use Upcycled Si Nanomaterials for Stable Operation of Lithium-Ion Batteries

Silicon, as a promising next-generation anode material, has drawn special attention from industries due to its high theoretical capacity (around 3600 mAh g−1) in comparison with conventional electrodes, e.g., graphite. However, the fast capacity fading resulted by a large volume change hinders the pragmatic use of Si anodes for lithium ion batteries. In this work, we propose an efficient strategy to improve the cyclability of upcycled Si nanomaterials through a simple battery operation protocol. When the utilization degree of Si electrodes was decreased, the electrode deformation was significantly alleviated. This directly led to an excellent electrochemical performance over 100 cycles. In addition, the average charge (delithation) voltage was shifted to a lower voltage, when the utilization degree of electrodes was controlled. These results demonstrated that our strategic approach would be an effective way to enhance the electrochemical performance of Si anodes and improve the cost-effectiveness of scaling-up the decent nanostructured Si material