T/GDBIA 06-2023 Active

Main technical content: 6.1 Sample processing: Three-element cathode materials are prepared according to GB/T 37201 for button-type batteries. The electrolyte used is a 1 mol lithium hexafluorophosphate (LiPF6) solution in ethylene carbonate/dimethyl carbonate/methyl ethyl carbonate (with a mass ratio of 1:1:1), or an electrolyte with equivalent performance. The assembled batteries are charged and discharged according to the standard GB/T 37201 and cycled three times. After that, they are charged at 0.2C to 4.2V and maintained at constant voltage until the current drops below 0.01C (with a limit time of 30 minutes). The fully charged batteries are placed in a glove box. After removing and disassembling the electrodes, the surface of the electrodes is cleaned with dimethyl carbonate to remove electrolyte decomposition products. The electrodes are then placed in the transition chamber of the glove box for vacuum drying overnight. The coating on the dried electrodes is scraped off, and the resulting powder is used as a test sample for DSC and ARC. 6.2 Measurement: An appropriate amount of prepared powder and an equivalent amount of electrolyte are placed in a DSC high-pressure crucible/ARC sample tube and sealed. DSC and ARC tests are then conducted. - DSC test: Using a high-pressure crucible with the electrolyte as a reference, the test is performed under an inert atmosphere of nitrogen at a heating rate of 5℃/min. The start and end temperatures can be set according to the characteristics of the sample. - ARC test: With a start temperature of 50℃ and an end temperature of 400℃ (which can be set according to the characteristics of the sample), a step temperature of 5℃ is used, with a waiting time of 15 minutes and a temperature rate sensitivity threshold of 0.02℃/min.