Robust high-temperature potassium-ion batteries enabled by carboxyl functional group energy storage

Significance Distinctively different from the popularly reported works, an energy storage mechanism is proposed for exploring robust high-temperature potassium-ion batteries (PIBs) with high cycle stability. This is based on an example of p-phthalic acid with two carboxyl functional groups as the redox centers. The cycle stabilities achieved under both low and high current densities are the best among those of high-temperature PIBs reported previously.