Aerogel high efficiency heat insulator (first generation, PI/PET package), also known as aerogel cell module heat insulator, is a customized heat insulator processed between the cells according to customer requirements. The heat insulator is mainly used to inhibit heat diffusion in the case of thermal runaway of the battery cell, and to delay the accident. When a single core thermal runaway situation, to ensure that in addition to the runaway core, the addition of heat insulation piece greatly reduces the other core due to the high heat conduction of the runaway core and trigger a chain of loss of control, to ensure that the escape of personnel and rescue time for the vehicle. At the same time, when the vehicle is working normally, the heat insulation piece can also absorb the excess stress generated by the bulging of the battery cell through its own multi-gap structure, which plays the role of cushioning and shock absorption.