Electrolyte for lithium iron phosphate lithium-ion battery

A lithium-ion battery and lithium iron phosphate technology, which is applied in secondary batteries, circuits, electrical components, etc., can solve the problems of limiting the application performance of lithium iron phosphate batteries, unsatisfactory low-temperature rate capacity, and poor high-temperature cycle performance of batteries. Good battery cycle performance, stable room temperature cycle performance, and suitable for low-temperature discharge

Inactive Publication Date: 2013-11-06
SHANGHAI JIAO TONG UNIV +1
View PDF2 Cites 12 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

A single solvent often cannot meet the requirements in terms of performance. It is necessary to optimize the ratio of solvent components and relative amounts to make the electrolyte have a higher dielectric constant and lower viscosity, so as to achieve the purpose of improving the low-temperature performance of lithium-ion batteries.
[0004] At present, lithium iron phosphate batteries use commercially widely used lithium hexafluorophosphate (LiPF 6 ) / ethylene carbonate (EC)+dimethyl carbonate (DMC) electrolyte, the battery has the problems of poor high-temperature cycle performance and unsatisfactory low-temperature rate capacity, which greatly limits the application performance of lithium iron phosphate batteries

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Electrolyte for lithium iron phosphate lithium-ion battery
  • Electrolyte for lithium iron phosphate lithium-ion battery

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] In this example, the solvent ethylene carbonate (EC), ethyl acetate (EA) and ethyl methyl carbonate (EMC) are mixed uniformly in a glove box with a humidity of less than 1% in a ratio of 1:1:1 by volume Make non-aqueous organic solvent, then add the mixed lithium salt that 3.1g LiTFSI and 0.233g LiBOB uniformly mix and form, after uniform mixing, get the mixed lithium salt solution that concentration is 1mol / L, wherein the mole of LiTFSI and LiBOB in the mixed lithium salt The ratio is 9:1. After the electrolyte salt is fully dissolved, leave it for 24 hours to obtain the high-low temperature electrolyte solution for lithium iron phosphate battery of the present invention.

[0016] After testing, using 1C rate discharge, the capacity retention rate of lithium iron phosphate battery at -20°C and -40°C is 64% and 40% respectively; the capacity retention rate after 100 cycles at room temperature is greater than 92.5%; high temperature (55°C ) under the condition of 70 cycl...

Embodiment 2

[0018] In this example, the solvent ethylene carbonate (EC), ethyl acetate (EA), ethyl methyl carbonate (EMC) and r-butyrolactone (GBL) were mixed in a volume ratio of 1:1:1:1 Mix evenly in a glove box with a humidity of less than 1% to make a non-aqueous organic solvent, then add 3.1g LiTFSI and 0.233g LiBOB to form a mixed lithium salt, and mix uniformly to obtain a mixed lithium salt solution with a concentration of 1mol / L , wherein the molar ratio of LiTFSI and LiBOB in the mixed lithium salt is 9:1, after the electrolyte salt is fully dissolved, it is left for 24 hours to obtain the high-low temperature electrolyte solution for lithium iron phosphate battery of the present invention.

[0019] After testing, using 1C rate discharge, the capacity retention rate of lithium iron phosphate battery at -20°C and -40°C is 63% and 43% respectively; the capacity retention rate after 100 cycles at room temperature is greater than 93.2%; high temperature (55°C ) under the condition o...

Embodiment 3

[0021] In this example, the solvent r-butyrolactone (GBL), ethylene carbonate (EC), ethyl acetate (EA) and ethyl methyl carbonate (EMC) were mixed in a volume ratio of 1:1:1:3 Mix evenly in a glove box with a humidity of less than 1% to make a non-aqueous organic solvent, then add 3.1g LiTFSI and 0.233g LiBOB to form a mixed lithium salt, and mix uniformly to obtain a mixed lithium salt solution with a concentration of 1mol / L , wherein the molar ratio of LiTFSI and LiBOB in the mixed lithium salt is 9:1, after the electrolyte salt is fully dissolved, it is left for 24 hours to obtain the high-low temperature electrolyte solution for lithium iron phosphate battery of the present invention.

[0022] After testing, using 1C rate discharge, the capacity retention rate of lithium iron phosphate battery at -20°C and -40°C is 60% and 40% respectively; the capacity retention rate after 100 cycles at room temperature is greater than 92.5%; high temperature (55°C ) under the condition o...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention discloses an electrolyte for a lithium iron phosphate lithium-ion battery. The electrolyte is prepared by uniformly mixing an electrolyte lithium salt and a non-aqueous organic solvent; the electrolyte lithium salt is a mixed lithium salt prepared by uniformly mixing lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and lithium bis(oxalate)borate (LiBOB) according to a molar ratio of 95-75%:5-25%; the concentration of the mixed lithium salt solution consisting of the electrolyte lithium salt and the non-aqueous organic solvent is 0.8-1.3 mol/L; and the non-aqueous organic solvent is prepared by uniformly mixing a conventional substrate solvent and a low-melting-point solvent with a volume percent ratio of 10%-50%:90%-50%. The electrolyte provided by the invention has a wider temperature window, better charging and discharging performances and good cycling stability, and is capable of giving consideration to high-temperature performances and low-temperature performances of the lithium iron phosphate lithium-ion battery.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to an electrolyte solution for lithium iron phosphate lithium ion batteries. Background technique [0002] With the continuous development of lithium-ion battery technology, it is expected that it can be applied to military, aviation, and especially the field of electric vehicles that has attracted much attention. Electric vehicles are the best way to solve the energy crisis and environmental pollution. "Energy-saving and new energy vehicles" represented by electric vehicles have become my country's strategic emerging industries. At present, lithium-ion batteries used in these fields need to be greatly improved in terms of high-temperature performance, low-temperature performance, cycle performance and safety performance. [0003] Lithium iron phosphate material due to its high safety. Low cost and long life, but also environmentally friendly, as a positive electrode...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): H01M10/0569H01M10/0568H01M10/0525
CPCY02E60/122Y02E60/10
Inventor 车海英杨军廖小珍马紫峰
Owner SHANGHAI JIAO TONG UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap