Redox couple for lithium ion battery overcharge-resistant mixed additive

A technology of mixing additives and lithium ion batteries, applied in the field of redox pairs, can solve problems such as reducing the overcharge protection performance of redox pairs additives, and achieve the effects of improving long-term cycle stability, improving safe use performance, and reducing permanent damage

Inactive Publication Date: 2011-04-06
HEFEI GUOXUAN HIGH TECH POWER ENERGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The invention patent with the publication number CN101577348A discloses "multiple overcharge protection functional electrolyte for lithium-ion batteries". Zeng Biao and others published "functional additives on lithium-ion Anti-overcharge Chemical Behavior of Batteries", these two documents put forward the advantages of using redox couple and electropolymerization mixed additives, but some of the redox couple additives and electropolymerization additives selected in the literature are generated during the overcharge protection mechanism. Without the irreversible polymerization reaction, the protection of the battery is still a "suicide" irreversible protection to a large extent, which seriously reduces the overcharge protection performance of the redox additive.

Method used

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  • Redox couple for lithium ion battery overcharge-resistant mixed additive
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  • Redox couple for lithium ion battery overcharge-resistant mixed additive

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0016] Add 1.50g of p-xylylene dimethyl ether, 3.10ml of tert-butanol and 5ml of glacial acetic acid in sequence in a 125ml Erlenmeyer flask equipped with ice bath and magnetic stirring. After stirring evenly, slowly add 10ml of concentrated sulfuric acid dropwise (5-7min) . After the addition of sulfuric acid is completed, remove the ice bath, continue to stir the whole reaction system at room temperature for 20 minutes until the reaction is complete, add 75ml of ice water, stir for 5 minutes, filter, and use 70ml of ice water and 10ml of ice water solution containing 10% methanol successively for the obtained crystals. After washing, the resulting crystals were recrystallized and purified with methanol aqueous solution, and dried in vacuum to obtain 2,5-di-tert-butyl-p-xylylene dimethyl ether with a yield of about 56.6%.

[0017] In an argon-filled glove box (H 2 O 6 / EC: EMC: DMC = 1: 1: 1 (w / w), two parts were placed in fluorinated bottles, and the first sample was added ...

Embodiment 2

[0019] 2,5-di-tert-butyl-p-phenylene diethyl ether was synthesized by using p-phenylene diethyl ether and tert-butanol as raw materials. The specific method was the same as in Example 1, and the yield was about 38.6%.

[0020] In an argon-filled glove box (H 2 O 6 / EC:EMC:DMC=1:1:1(w / w), then add 2,5-di-tert-butyl-p-phenylenediethyl ether additive to saturation, then add 5wt.% biphenyl, use two kinds of Electrolyte made of LiFePO 4 / / Graphite button battery, charged at 0.2C for 10h (100% overcharge), and then discharged at 0.2C to end voltage 2.0V. The results show that in the first 51 overcharge cycles of the battery, 2,5-di-tert-butyl-p-phenylenediyl ether can effectively clamp the voltage on a voltage platform of about 4.0V, but from the 52nd time onwards, the voltage platform It gradually disappears, and the voltage rises rapidly. At the 54th overcharge, the voltage rises slowly to about 4.5V, until a new voltage platform appears at about 4.7V, and then the battery volta...

Embodiment 3

[0022] Using MCM-41 molecular sieve loaded with scandium trifluoromethanesulfonate as catalyst, phenol / tert-butanol as raw material, supercritical CO at 130 °C 2 Reaction in the system for 6 hours, separation and purification of the product by column chromatography to obtain 2,4,6-tri-tert-butylphenol with a yield of 32.6%, and then to 2,4,6-tri-tert-butylphenol at 2 SO 4 Aqueous solution, then raise the reaction temperature to 80°C, react for 4 hours, the product is separated and purified by column chromatography to obtain 1,3,5-tri-tert-butyl-2-methoxybenzene with a yield of 76.3%.

[0023] In an argon-filled glove box (H 2 O 6 / EC:EMC:DMC=1:1:1(w / w), add 1,3,5-tri-tert-butyl-2-methoxybenzene to its saturation concentration, then add 3wt.% cyclohexylbenzene , using this electrolyte containing mixed additives to make LiFePO 4 / / Graphite button cell. The 100% overcharge test results show that 1,3,5-tri-tert-butyl-2-methoxybenzene can effectively clamp the voltage on the vol...

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PUM

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Abstract

The invention discloses a redox couple for a lithium ion battery overcharge-resistant mixed additive, belonging to the technical field of lithium ion battery overcharge protection additives. The invention aims to provide the redox couple for a lithium ion battery overcharge-resistant mixed additive, which has better circulation stability and high steric effect, so that polymerization cannot be carried out on the redox couple per se in the overcharge protection process, and meanwhile, the redox couple per se and an electric polymerization monomer are not reacted in the presence of the electric polymerization monomer so that the overcharge protection performance of the redox couple is improved. The redox couple additive is an aromatic ring class compound containing two or more high steric-hindrance substituents, and the addition quantity is saturated concentration in electrolyte. The redox couple per se is not polymerized and not reacted with the electric polymerization monomer. In the use process of the redox couple / electric polymerization mixed additive, two overcharge protection systems separately and sequentially protect the battery, thus, the safe use performance of the battery is improved.

Description

Technical field: [0001] The invention relates to a redox pair used in a lithium-ion battery anti-overcharge mixed additive, and belongs to the technical field of lithium-ion battery overcharge protection additives. Background technique: [0002] The safety of lithium-ion batteries has attracted more and more attention. Overcharging triggers a violent chemical reaction inside the battery, which eventually leads to thermal runaway of the battery, which is the main reason for the safety problems of lithium-ion batteries. In the case of failure or abuse of the battery management system, the battery is in danger of being overcharged. If a self-voltage control mechanism can be established inside the battery, that is, it will not damage the normal use of the battery after charging protection. is more practical. Therefore, the research and innovation of the internal overcharge protection mechanism of the battery is an important link in the development of lithium-ion batteries. ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M10/42H01M10/0567
CPCY02E60/12Y02E60/10
Inventor 杨续来徐小明刘大军韦佳兵
Owner HEFEI GUOXUAN HIGH TECH POWER ENERGY
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