Electrochemical Behavior of Li−CNT Composite Powder Electrodes for Stable Lithium Anodes

Abstract

Li metal is considered a highly desirable anode material for next-generation high-energy-density rechargeable lithium batteries because of its extremely high specific capacity (3860 mAh g-1), large negative standard reduction potential, low mass density, and ability to enable battery chemistries with lithium free cathode materials. However, the practical application of Li metal anodes is still prohibited by its low Coulombic efficiency, uncontrolled dendritic growth, and poor solid electrolyte interphase (SEI) during the Li dissolution /deposition. Here, A new type of Li−CNT composite powder electrode (Li−CNT CE) was fabricated via mechanical blending of Li powders and CNT Ball produced by a spray dryer. The Li-CNT CE can suppress dendrite formation with its isolated Li powder and low current density caused by the large specific surface area of spherical Li powder. In our cycle life test of symmetric Li-CNT CE, void spaces between spherical Li powders and CNT Balls contributes to stable longer cycling properties, which works for more than 1000h, because it inhibits inevitable volume changes. Moreover, high electrical conductivity of CNT ball and lighter battery weight due to low mass density of CNT ball is sure of an advantage for the automotive battery. This work provides new insights into the development of Li powder and CNT Ball composite electrode for achieving dendrite-free, high CE and Low mass density Li-metal anodes in Li metal secondary battery (LMSB).