Analysis of the material field of lithium batteries
The CR2032 battery made of high-temperature manganese dioxide material developed by our company has been tested for electrical performance and shelf durability at room temperature, low temperature and high temperature (125℃, 150℃). The specific capacity of this material reaches 260mAh /g above, the discharge curve is stable, and the manganese dioxide material remains relatively stable at high temperatures. This material is completely suitable for working at high temperatures and can be used as a positive electrode material for TPMS batteries. High-temperature lithium manganese dioxide batteries are an important primary power source and are widely used in automotive tire pressure measurement systems (TPMS) and medical instruments. Although my country is a big country in the manufacture of primary batteries, it is in a blank state in the field of high-end high-temperature primary lithium batteries. The lack of cathode materials suitable for high-temperature applications is one of the reasons that limit the development of high-temperature lithium manganese dioxide batteries. Above 100℃, the reaction between manganese dioxide and the electrolyte becomes stronger, which promotes the decomposition of the electrolyte and produces a large amount of gas, and the formation of an inert oxide layer on the surface of the manganese dioxide causes an increase in ohmic polarization. The performance of the manganese oxide battery deteriorates at high temperature and cannot work. The company has conducted in-depth research on manganese dioxide cathode materials suitable for high temperature use, starting with controlling the ratio of manganese dioxide γ to β crystal form, and doping with elements to obtain high temperature manganese dioxide (G-MnO2). Material performance test method: According to the ratio of high-temperature manganese dioxide: conductive agent: adhesiveu003d92:4:4, ethanol is used as the solvent, and the positive electrode sheet is made by rolling film. The obtained positive electrode sheet, lithium sheet, polypropylene separator, and electrolyte were assembled into a CR2032 battery for testing. Battery test results: 1. At room temperature (20±5°C), discharge at a constant current (8-3-1.5-0.6-0.3mA/g) with a cut-off voltage of 2.0V, and the specific capacity of the positive electrode material is 264mAh/g. 2. At low temperature (0±2℃), discharge at a staged constant current (16-8-3-1.5-0.6-0.3mA/g), the discharge curve fluctuates due to temperature changes, and the discharge specific capacity of the material is 261mAh/ g. 3. At a high temperature of 125°C, the battery is discharged with a constant current of 16mA/g, the cut-off voltage is 2.0V, the battery can be discharged normally, the discharge curve is stable, and the specific capacity of the positive electrode material is 260mAh/g. Obviously, the high current discharge capability of the material is better at high temperature. 4. Leave the battery at 125°C for 120 hours, then discharge at a constant current of 16mA/g, the discharge cut-off voltage is 2.0V, and the specific capacity of the cathode material is 250mAh/g, indicating that the high-temperature cathode material remains relatively stable at 125°C. The degree of decomposition or deterioration is small. 5. The battery was discharged at a constant current of 16mA/g at 150°C and tested for 8 hours, which exceeded the 7-hour working requirement of the TPMS system at 150°C. The battery's working voltage platform is normal, and no abnormal platform appears, indicating that the positive electrode material has no new phases, the nature is stable, and the battery can continue to discharge.