NMC811-Li6PS5Cl-Li/In All-Solid-State Battery Capacity Attenuation Based on Temperature-Pressure-Electrochemical Coupling Model

Abstract

Solid-state batteries have been widely studied due to their unique advantages such as high mechanical strength, good temperature adaptability, and long cycle life. However, the coupling effect of external pressures and ambient temperatures on the cycle performance of solid-state batteries has not been systematically elucidated. Based on the finite element simulation, this work establishes a temperature-pressure-electrochemical coupling model to assess the coupling effect of temperature and pressure on the cycle capacity decay of solid-state batteries. Taking an NMC811-Li6PS5Cl-Li/In solid-state battery as an example, the results show that the optimal pressure range of the battery is 127.38 MPa-254.76 MPa. Applying external stress to a solid-state battery can significantly reduce its capacity decay rate, 191.07 MPa was selected in the optimal stress interval, ten cycles of charge-discharge cycle experiment were carried out on NMC811-Li6PS5Cl-Li/In battery at an ambient temperature of 60 °C, the tenth turn capacity of this battery only decays to 97.78% of the initial capacity, while the tenth turn capacity of the non-pressure battery decays to 96.57%. The model established in this study provides an effective approach for finding the optimal external pressure range for solid state batteries, which will contribute to the development of batteries with longer cycle life.