Improving Cycling Performance of Anode-Free Lithium Batteries by Pressure and Voltage Control

Anode-free lithium batteries (AFLBs) have great potential to provide a higher energy density than most other batteries. However, the performance of AFLBs is very sensitive to pressure and other operating parameters. In this work, the operating voltage range and the internal pressures applied to AFLBs using a localized high-concentration electrolyte have been optimized for the coin cells widely used in the early stage research of AFLBs. With an optimized cycling protocol, a thin layer of uniform nucleation sites can be formed during the initial cycle, which will facilitate smooth Li deposition/stripping in the subsequent cycles of AFLBs. The solid-electrolyte interphase layer formed under optimized pressure and uniform pressure distribution exhibits good stability for long-term cycling. The internal pressure in the coin cells has been optimized to improve the cycling performance of AFLBs (Cu||NMC811) with 72% capacity retention in 100 cycles.