High-temperature-resistant lithium ion battery

Abstract

The invention belongs to the field of a lithium ion secondary battery and particularly relates to a high-temperature-resistant lithium ion battery. The battery comprises a positive electrode materialLiNiXCoyMnZO2, a negative electrode material and a high-temperature-resistant electrolyte, wherein the high-temperature-resistant electrolyte comprises non-aqueous organic solvent, lithium salt and additive, the lithium salt at least comprises one lithium salt which does not react with H2O to generate HF. The invention discloses a lithium ion battery suitable for being used in a high-temperature environment of 60-80 DEG C, the battery can be stably used in a high-temperature environment, the high-temperature storage bulge is small, and the battery is long in cycle life and high in capacity retention ratio at high temperature.

Description

technical field [0001] The invention belongs to the field of lithium ion secondary batteries, in particular to a high temperature resistant lithium ion battery. Background technique [0002] Due to its high energy density, long cycle life, wide operating temperature range, and environmental protection, lithium-ion batteries have become the main energy provider of mobile electronic devices and are widely used in various environments. [0003] However, in high-temperature environments, such as mobile electronic devices exposed to the sun outdoors, communication power supplies, energy storage base stations, some mobile power systems with limited space, poor heat dissipation performance or no heat dissipation device, vehicle system power supplies, etc. or even higher. Ordinary lithium-ion batteries are prone to gas production in a high-temperature environment above 60°C, and the battery capacity decays quickly, etc., which make ordinary lithium-ion batteries unusable or frequen...

AI Technical Summary

Problems solved by technology

Ordinary lithium-ion batteries are prone to gas production in a high temperature environment above 60°C, and the battery capacity decays quickly, which makes ordinary lithium-ion batteries unusable or frequently replaces the power supply.

Analysis of the main reasons for the failure of the power supply performance is as follows: 1. The oxidation of the electrolyte by the positive electrode at high temperature produces CO 2 and H 2 O, H 2 O reacts with lithium salts to generate HF, which destroys the CEI of the positive electrode and the SEI of the negative electrode to generate CO 2 Gas, after the SEI film is destroyed, the electrolyte solvent and graphite undergo a reduction reaction to produce alkane gas, and the accumulation of adverse reactions leads to battery swelling and rapid capacity decay

2. Under the corrosion of HF at high temperature, the metal ions of the positive electrode material are dissolved, the structure changes, and a new structural phase is formed, which leads to the capacity decay of the positive electrode material, and the deposition of metal ions on the surface of the negative electrode blocks the SEI film. The decomposition of SEI film is accelerated, and the battery performance deteriorates rapidly

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