Recent research pushes boundaries in energy storage and safety. A novel dual-passivation polymer strategy advances the stability of lithium-metal batteries by engineering a robust solid-electrolyte interphase, addressing dendrite formation and electrolyte reactivity challenges. Additionally, an all-in-one halide cathode material, Li₁.₃Fe₁.₂Cl₄, offers enhanced ionic and electronic conductivity for solid-state battery applications, promising higher energy densities and mechanical stability. Complementing these advances, Drexel University developed ultrasonic techniques to detect latent defects in lithium-ion batteries, mitigating thermal runaway risks and enhancing manufacturing reliability.