Positive paste of rapid-charge and rapid-discharge type high-power lithium ion battery and manufacturing method

Abstract

The invention discloses a positive paste of a rapid-charge and rapid-discharge type high-power lithium ion battery and a manufacturing method. The positive paste comprises 10 to 35 parts of an activesubstance A, 62 to 81 parts of an active substance B, 1 to 3 parts of a conductive agent A, 1 to 3 parts of a conductive agent B and 1 to 3 parts of an adhesive A, wherein the active substance A is lithium cobalt oxide LiCoO2, lithium nickelate LiNiO2, lithium manganate LiMn2O4, lithium iron phosphate LiFePO4, lithium manganese phosphate LiMnPO4, manganese lithium iron phosphate LiFexMn1-xPO4 or lithium vanadium phosphate Li3V2(PO4)3; the active substance B is lithium nickel-cobalt manganate LiNixCo1-x-yMnyO2, wherein x+y is smaller than 1; the conductive agent A is a Ketjen Black or carbon nanotube; the conductive agent B is graphene or Super-P; and the adhesive A is modified polyvinylidene fluoride PVDF. By adopting the lithium ion battery, high power, rapid charge and rapid discharge can be met, and the service life is long.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion battery preparation, and relates to a positive electrode paste of a fast-charging and fast-discharging high-power lithium-ion battery and a manufacturing method thereof. Background technique [0002] Lithium-ion secondary battery has now become the mainstream chemical power source, and is widely used in most mobile terminal equipment and new energy vehicles. Long life and other advantages. In recent years, with the rapid development of electric tools, unmanned aerial vehicles, aircraft models, and new energy vehicles, especially with the batch application of lithium-ion batteries in HEV hybrid vehicles and 12V / 48V vehicle start-stop systems, lithium-ion secondary The charging and discharging power requirements of the battery are getting higher and higher, and generally need to meet the 30-40C rate charging and discharging requirements, but it is difficult for commercial lithium-ion batteries ...

AI Technical Summary

Problems solved by technology

In recent years, with the rapid development of electric tools, unmanned aerial vehicles, aircraft models, and new energy vehicles, especially with the batch application of lithium-ion batteries in HEV hybrid vehicles and 12V / 48V vehicle start-stop systems, lithium-ion secondary The charging and discharging power requirements of the battery are getting higher and higher, and generally need to meet the 30-40C rate charging and discharging requirements, but it is difficult for commercial lithium-ion batteries to meet such high-power charging and discharging requirements.

[0003] The vehicle-mounted power lithium-ion battery needs to face three basic requirements: first, long life, the warranty period is generally required to be 5-8 years or 80,000-100,000 kilometers, but the lithium-ion battery is in the cycle of charging and discharging. The polarization of the battery will continue to increase, causing the battery life to not meet the usage requirements

The second is high power, but the lithium-ion battery will increase the polarization of the battery under the condition of high current charging and discharging, and the battery will generate serious heat, which will increase the side reaction, and then cause the battery capacity to decay, resulting in the power of the battery not meeting the use requirements.

The third is a wide temperature range, which needs to meet the requirements of the working range of -20°C-60°C, but the polarization of lithium-ion batteries will increase significantly under low temperature conditions, resulting in lithium deposition and capacity attenuation, so that it cannot be used under low temperature conditions. use

Traditional power lithium-ion batteries are relatively easy to meet high-rate continuous or pulse discharge, but under high-rate continuous charging or pulse charging, lithium-ion batteries are prone to lithium deposition, resulting in irreversible capacity loss of the battery, and even local lithium dendrites produce internal short circuits and cause This leads to thermal runaway of the battery, especially at low temperatures