Enhancing the cycling performance of MgH2–LiBH4 based solid-state batteries via stacking pressure tailoring

Abstract

MgH₂ has been considered a promising anode material for all-solid-state batteries (ASSBs) due to its high theoretical capacity, low voltage plateau (0.5 V vs. Li⁺/Li), and minimal voltage hysteresis. Herein, by applying 25 MPa stacking pressure, the interfacial issues caused by the volume expansion of MgH₂ electrodes can be well suppressed, which ultimately improves the electrochemical performance of the MgH₂ anode material. The MgH₂ half-cell achieves a high capacity of 1212 mA h g⁻¹ after 200 cycles at 0.5C. When assembled with a S cathode, the Mg–LiH|LiBH₄|S full cell delivers a high specific capacity of 1300 mA h g⁻¹ at 0.1C and stably operates over 100 cycles. This work provides a facile strategy to improve the performance of the MgH₂ anode in ASSB devices via stacking pressure tailoring.