High-Energy-Density, Long-Life Li-Metal Batteries via Application of External Pressure

The application of commercially available carbonate-based electrolytes to Li-metal batteries (LMBs) is challenging because of the uncontrollable side reactions of the electrolytes with Li anodes. Herein, a practical carbonate-electrolyte-based LMB with a high areal capacity and long cycle life is proposed. The cycling stability of the proposed LMB is established by applying an external compressive pressure (1200 kPa) and a boehmite-coated separator to prevent the short circuit of the electrodes. The external pressure drives the growth of the Li metal as a dense uniform layer instead of dendrites and mitigates the formation of microcracks in the charged Ni-rich layered cathode. The unprecedented cycling stability of the stacked LMB with a Ni-rich layered cathode, retaining 82.0% of its initial capacity after 500 cycles, can prove instrumental in realizing practical high-energy-density LMBs, thus demonstrating the possibility of employing cell compression to increase the life and energy density of LMBs.