Combustion-resisting electrolyte of lithium secondary cell and its lithium cell

Abstract

The invention discloses a flame-proof electrolyte and its lithium battery for secondary lithium battery, which is characterized by the following: adopting one or more phosphosubester (such as methyl acid phosphate dimethyl ester, ethyl phosphate diethyl ester and its derivant) as pure solvent or solvent component; reducing the price of electrolyte with incombustibility, low toxicity and high conductivity; improving the combusting safety effectively.

Description

technical field

[0001] The invention relates to a flame-retardant electrolyte solution for a lithium secondary battery. It specifically relates to an electrolytic solution using one or more than one phosphoric acid ester as a pure solvent or a solvent component, and belongs to the technical field of electrochemical and chemical power supply products. Background technique

[0002] With the rapid development of information technology and the increasing popularity of portable electronic devices, the demand for high specific energy batteries is increasing year by year. Lithium-ion batteries have significant advantages such as high voltage, low self-discharge rate, and high energy density, and are gradually replacing traditional batteries and expanding their application fields and market share.

[0003] However, the potential safety hazards of lithium-ion batteries have always been the primary concern of applications. At present, the electrolyte used in lithium batteries is a f...

Examples

Embodiment 1

[0034] Lithium bisoxalate borate (LiBOB) and 10% VC were added to dimethyl methyl phosphate (DMMP) to form a 0.6M LiBOB+DMMP solution. Inject the electrolyte into graphite / LiCoO 2 Charge and discharge experiments were carried out in the battery (as attached figure 2 ). It can be seen from the figure that the efficiency in the first week can reach 86%, which is close to the initial efficiency of the traditional carbonate electrolyte, and the cycle performance is good.

Embodiment 2

[0036] At 1M LiPF 6 / EC-DMC (1:1) solution was added with 20% diethyl ethyl phosphate. The electrolyte solution was added to a commercial LiMn204-C lithium-ion battery. Depend on image 3 It can be seen that, except for a slight decrease in the charge and discharge efficiency of the battery in the first week (~84%), the charge and discharge efficiency of the battery subsequently rises rapidly to ~100%, and the charge and discharge voltage platform is exactly the same as that without the flame retardant, indicating that this Flame retardants can also be used as safety additives in practical batteries.

Embodiment 3

[0037] Example 3: Lithium hexafluorophosphate (LiPF 6 ) into 0.6M Li LiPF 6 +DMMP+DEMP solution. Inject the electrolyte into commercial graphite / LiCoO 2 In batteries, the prepared commercial graphite / LiCoO 2 Initial efficiency was -84%.

technical field

[0001] The invention relates to a flame-retardant electrolyte solution for a lithium secondary battery. It specifically relates to an electrolytic solution using one or more than one phosphoric acid ester as a pure solvent or a solvent component, and belongs to the technical field of electrochemical and chemical power supply products. Background technique

[0002] With the rapid development of information technology and the increasing popularity of portable electronic devices, the demand for high specific energy batteries is increasing year by year. Lithium-ion batteries have significant advantages such as high voltage, low self-discharge rate, and high energy density, and are gradually replacing traditional batteries and expanding their application fields and market share.

[0003] However, the potential safety hazards of lithium-ion batteries have always been the primary concern of applications. At present, the electrolyte used in lithium batteries is a f...

Examples

Embodiment 1

[0034] Lithium bisoxalate borate (LiBOB) and 10% VC were added to dimethyl methyl phosphate (DMMP) to form a 0.6M LiBOB+DMMP solution. Inject the electrolyte into graphite / LiCoO 2 Charge and discharge experiments were carried out in the battery (as attached figure 2 ). It can be seen from the figure that the efficiency in the first week can reach 86%, which is close to the initial efficiency of the traditional carbonate electrolyte, and the cycle performance is good.

Embodiment 2

[0036] At 1M LiPF 6 / EC-DMC (1:1) solution was added with 20% diethyl ethyl phosphate. The electrolyte solution was added to a commercial LiMn204-C lithium-ion battery. Depend on image 3 It can be seen that, except for a slight decrease in the charge and discharge efficiency of the battery in the first week (~84%), the charge and discharge efficiency of the battery subsequently rises rapidly to ~100%, and the charge and discharge voltage platform is exactly the same as that without the flame retardant, indicating that this Flame retardants can also be used as safety additives in practical batteries.

Embodiment 3

[0037] Example 3: Lithium hexafluorophosphate (LiPF 6 ) into 0.6M Li LiPF 6 +DMMP+DEMP solution. Inject the electrolyte into commercial graphite / LiCoO 2 In batteries, the prepared commercial graphite / LiCoO 2 Initial efficiency was -84%.

Images