High-performance ZnS@graphite composites prepared through scalable high-energy ball milling as novel anodes in lithium-ion batteries

A ZnS@graphite composite was developed using a high-energy mechanical milling (HEBM) for use as an anode in lithium-ion batteries. Compared to previous studies on ZnS-based electrodes prepared using different processes, the HEBM is advantageous because of its simplicity, scalability, and greater performance. In this work, we mainly focused on the finding of optimal carbon-based matrix that can significantly enhance the performance of ZnS-based composite electrode. In comparison with other types of ZnS-based composites, ZnS@graphite exhibited superior performances with a reversible capacity of 444 mA h g(-1) after 300 cycles for the half cell (capacity retention of 71% compared to that of the 2nd cycle), 117 mA h g(-1) after 50 cycles for the full cell (energy density of 363 W h kg(-1)), and excellent rate capability (80% capacity retention at 3000 mA g(-1) compared with that at 100 mA g(-1)). This is attributed to higher surface area (associated with solid-lubrication of graphite), homogeneous mixing, and high electrical conductivity as confirmed by various characterizations including BET, HRTEM, SEM, and sheet resistance measurements. The origin of the improved cyclic stability and rate capability of ZnS@graphite over other ZnS-based electrodes was further investigated by CV, EIS, and ex situ SEM. (C) 2019 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.