Lithium-ion batteries (LIBs) are widely recognized as advanced energy storage systems (ESSs) due to their enhanced power capacity, extensive charging–discharging efficiency, and extended lifespan. However, the chemical and electrochemical interactions resulting in the uncontrolled exothermic reaction of LIB components should be considered when numerous fire or explosive incidents occur sporadically worldwide. Due to the characteristics of these active materials, an improved understanding of their thermal instability, their thermokinetic mechanisms when an LIB powers an electric system, and especially their reactivity is required as an alternative goal of proactive loss prevention. Calorimetric tests and thermal analysis techniques are introduced to determine an LIB's electrochemical and chemical reactions, which include the interaction among active components, thermal decomposition, and short circuits. The heat accumulation of an LIB affected by its components can result in a thermal explosion. Analytical thermokinetic equations are proposed to determine LIBs' exothermic reaction and create a self-heating model. The knowledge of an LIB's complex electrochemical and chemical reactions in case of thermal runaway from the calorimetry is subjected to fires or explosions. The advanced ESS of LIBs requires a proper thermal management system and a feasible, safe design. • The LIB megapack used in an EV or ESS has an emerging fire concern. • The thermal runaway to explosion transition of an LIB is related to temperature. • Thermal explosion energy involves heat and blast waves for energetic LIBs. • Calorimetry and thermokinetic analysis provide safety evaluation on LIBs.