Lithium manganese iron phosphate secondary battery and device

By controlling the electrolyte composition and forming a dense solid electrolyte interface membrane, the problem of poor cycle stability of lithium manganese iron phosphate secondary batteries under high voltage and high temperature is solved, and long life and improved safety are achieved under high voltage and high temperature conditions.

CN120809974AActive Publication Date: 2025-10-17XIFENG 2D FUJIAN MATERIAL TECH CO LTD
5 Cites 1 Cited by

Patent Information

Application Number
CN202511293636.4
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2025-09-11
Publication Date
2025-10-17
Estimated Expiration
2045-09-11

AI Technical Summary

Technical Problem

Lithium manganese iron phosphate secondary batteries have poor cycle stability under high voltage and high temperature conditions, resulting in rapid degradation of battery performance.

Method used

By precisely controlling the content of vinylene carbonate and ethylene carbonate in the electrolyte and strictly limiting the content of fluoroethylene carbonate and boron, a dense solid electrolyte interface film (CEI/SEI) is formed, which inhibits the dissolution of manganese ions and improves the cycle life of the battery at high voltage and high temperature.

Benefits of technology

The cycle life of the battery under high voltage and high temperature is significantly improved. The capacity retention rate is >80% after 2200 cycles at 4.25V/45℃, and >80% after 700 cycles at 4.25V/60℃, which reduces production costs and improves battery safety performance.

✦ Generated by Eureka AI based on patent content.
Patent Text Reader

Abstract

The invention discloses a lithium manganese iron phosphate secondary battery and device, and relates to the technical field of lithium manganese iron phosphate batteries. The lithium manganese iron phosphate secondary battery comprises an electrolyte and a positive pole piece, wherein the positive pole piece comprises a lithium manganese iron phosphate positive pole material; the electrolyte comprises an additive and an organic solvent, the additive comprises vinylene carbonate, and the mass of the vinylene carbonate accounts for 0.8%-1.7% of the total mass of the electrolyte; the organic solvent comprises ethylene carbonate, and the mass of the ethylene carbonate is 10-19% of the total mass of the electrolyte; the mass content of the fluorine element in the electrolyte is 7.5%-12.75%; the mass content of fluoroethylene carbonate in the electrolyte is less than 10 ppm, and the mass content of boron is less than 10 ppm. According to the invention, the contents of vinylene carbonate, ethylene carbonate and total fluorine element in the electrolyte are accurately controlled, and meanwhile, the contents of fluoroethylene carbonate and boron element are strictly limited to be less than a preset threshold value, so that the dissolution of manganese ions is effectively inhibited, and the cycle life of the battery at high voltage and high temperature is remarkably prolonged.
Need to check novelty before this filing date? Find Prior Art