Anode Performance and Safety Evaluation of Potassium-Ion Batteries

With the high cost and scarcity of lithium, alternative metal-ion battery systems need to be developed for scalable, inexpensive and large scale energy storage devices. Potassium-ion batteries (KIBs) have recently shown promise due to their capability to reversibly intercalate in graphite, the standard lithium-ion anode, for a specific capacity of 279 mAh/g. Recently, we have explored various carbonaceous and inorganic intercalation materials as anodes in KIBs with impressive rate performance and cycling stability. Electrochemical and material characterization enabled understanding of how the bulky ion and resulting volumetric changes upon cycling affects the semi-graphitic/graphitic anode material, as well as the electrochemical mechanisms during potassiation. In addition, to evaluate their applicability, we have investigated the safety of these materials in KIBs, in terms of thermal runaway range, degradation reaction identification, and enthalpy of reactions caused by degradation of secondary electrolyte interphase leading to exothermic heat generation.