Solid-State Electrolyte Separators for Li Metal Batteries: Using an Interlayer to Increase Rate Performance and Reduce Stack Pressure

From a balance-of-pack perspective it is advantageous for solid-state batteries to have the same operational specifications as those of conventional Li-ion batteries. For example, the additional module hardware required to maintain high stack pressure on solid-state batteries may reduce pack level energy density. With this in mind, GM R&D has developed semi-solid battery technologies that reduce the need for high stack pressure. We will show that our semi-solid test cells delivered a critical current density of 3.0 mA/cm2 at 25 °C and 0.1 MPa, which is nearly double the critical current density of comparable dry test cells cycled at 30x higher stack pressure.