To address the challenge of power lithium-ion batteries being difficult to handle both high and low temperatures, and in response to the demand for wide-temperature range power lithium-ion batteries in a certain special equipment, a ternary lithium-ion battery for a certain special equipment was taken as the research object. The research was carried out through the modification of graphite anodes and electrolytes to break through the performance barriers of power lithium-ion batteries under wide temperature range conditions. In this study, 200Wh/kg ternary lithium-ion battery cells and 3 series and 6 parallel modules were used as test prototypes. Through innovative technologies such as graphite anode material coating technology and the use of high-conductivity electrolytes, tests such as rate testing, cycle testing, vibration, and thermal shock of single cells were carried out to explore the wide temperature range characteristics of lithium-ion battery cells and modules. Based on the test results, it was concluded that Under the condition of a high current density of 25℃ and 20C, the retention rate of the discharge capacity of a single battery cell is 95.24%. The performance of the battery module shows obvious wide temperature range characteristics. For example, under the conditions of -55℃ and 0.2C current density, the retention rate of discharge capacity is 84.8%. Under the conditions of 55℃ and 1C current density, the retention rate of discharge capacity reaches 99.4%. Tests show that the battery cells and modules have been verified in application environments such as high temperature, low temperature and vibration, and their performance has reached the leading level in China.

Lithium-ion battery, Wide temperature, range, Special equipment, Modification, Capacity retention rate