Study on critical ambient temperature of cylindrical battery

In order to study the thermal safety of cylindrical battery and solve the three-dimensional cylindrical battery thermal explosion problem, a common thermal explosion physical model of cylindrical battery and three-dimensional thermal explosion mathematical model of cylindrical fireworks with non-uniform heat dissipation of the lateral surface were established for the first time. By applying the theory of heat transfer, the boundary conditions of cylindrical battery were simplified reasonably. The seven-point difference method was introduced to disperse the model. The three-dimensional numerical program was written by homotopy continuation method and Newton iteration method based on Matlab. Comparison of two-dimensional numerical solutions obtained by taking φ = 0 and classical solutions proved the accuracy of model. A common kind of fireworks was calculated in this paper. When this single cylinder firework stored individually, the criterion of thermal explosion is 1.796, and critical ambient temperature is 450.484 K. When stored in combination form (that is battery), the criterion of thermal explosion is 1.363 and critical ambient temperature is 447.964 K. The results show that the cylindrical fireworks stored in combination form is more dangerous than this single cylinder firework stored individually, so the cylindrical battery is the focus of safety prevention of fireworks.