Rapidly discharged/charged high power lithium ion battery and manufacturing method thereof

Abstract

The invention discloses a rapidly discharged / charged high power lithium ion battery and a manufacturing method thereof. The positive current collector comprises an aluminum foil and a conductive coating. The negative current collector comprises a copper foil and a conductive coating. The diaphragm is a PE material, which is bidirectionally and synchronously stretched, and ceramic oxide is paintedon the surface of the PE material. The anode paste comprises following components in parts by weight: 10 to 35 parts of lithium cobaltate, lithium nickelate, lithium manganate, lithium iron phosphate,lithium manganese phosphate, lithium iron manganese phosphate, or lithium vanadium phosphate, 62 to 81 parts of nickel cobalt lithium manganate, 1 to 3 parts of Ketjen black or carbon nanotube, and 1to 3 parts of graphene or Super-P and modified 1,3-polyvinylidene fluoride. The cathode paste comprises following components in parts by weight: 55 to 75 parts of artificial graphite or meso-phase carbon micro beads, 20.5 to 36 parts of soft carbon or hard carbon, 1 to 2 parts of CMC, 2 to 4 parts of Super-P, and 1.5 to 3 parts of styrene butadiene rubber SBR or polystyrene-acrylate. The providedlithium ion battery can continuously discharge or charge (30C). The 30C constant current charge capacity can account for 70% or more of 1C capacity, and the 30C discharge capacity can account for 90%or more of 1C capacity.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion battery preparation, and relates to a fast-charging and fast-discharging 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 to meet such high-power charging and disc...

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