Reaction mechanism study and modeling of thermal runaway inside a high nickel-based lithium-ion battery through component combination analysis

•Abnormal reaction mechanism is elucidated through component combination experiments.•Primary reaction pathways and onset temperature for each reaction are identified.•The effect of component interactions on thermal runaway reactions is examined.•A highly accurate reaction model is developed to simulate thermal runaway processes.•The change in mass and volume of components and internal pressure can be estimated.