Lattice‐Level Negative Thermal Expansion Enables Thermomechanical Self‐Compensation in High‐Rate Lithium Batteries
Localized Joule heating in high‐rate lithium metal batteries often induces severe thermomechanical failure of polymer separators and accelerates thermal runaway in cells with Ni‐rich NCM cathode. Here we report a multiscale separator design strategy that translates lattice‐level negative thermal expansion into macr...