Thermal stability of The Electrolyte

wallpapers Innovations 2020-02-14

This paper introduces the research progress of lLithium-ion battery protection from the thermal stability of electrolyte.

1、Lithium-ion battery thermal runaway threat

The principle warmth production of lithium-ion batteries comes from the electrolyte. To resolve the battery protection trouble, we should adhere to the precept of intrinsic protection, starting from the fine and poor materials and the electrolyte composition.

Explore the way to enhance the composition to enhance the protection of the battery, whilst ensuring a balance between protection and economic benefits.because of a chain of exothermic chemical reactions inside the electrolytebeneath the action of excessive temperature, the irreversible warmth of the battery accumulates plenty.  A good way to prevent the unfold of thermal runaway, it's miles in particular crucial to installation way to block the prevalence of protection accidents, such as insulation substances and cooling measures among battery cells. Also keep in mind whether or not within the event of a fireplace and explosion twist of fate, a way to store the loss to a minimal, that is, there ought to be corresponding hearth-fighting an effort to advantage a deeper knowledge of the danger of thermal runaway, it will be analyzed inside the following content.

2、electrolytethermal balance analysis

The thermal balance of the electrolyte is laid low with the combination of the alkyl carbonate natural solvent and the lithium salt. To be able to optimize the overall performance of the battery, the alkyl carbonate organic solvent needs to meet the characteristics of a huge working temperature range and high conductivity. Typically used organic solvents are especially cyclic carbonate compounds which include ethylene carbonate (EC), propylene carbonate (laptop), and chain carbonates, which include dimethyl carbonate (DMC), diethyl carbonate (DEC), carbonic acid. Methyl Ethyl Ester (EMC).

Lithium salts are specially LiPF6. LiBF4. LiBOB, LiTFSI, etc. Electrolyte lithium salt should meet the characteristics of properly thermal stability, excessive ionic conductivity, and true solubility. The thermal stability of the electrolyte gadget is particularly affected by environmental situations, which are complex and variable. The thermal stability of the lithium salt itself isn't like the thermal stability of the electrolyte. The thermal risk of the electrolyteis bigger than that of the blended natural solvent without lithium salt.

Based on the C80 microcalorimeter evaluation, the thermal stability of the four lithium salts in argon is LiTFSI < LiPF6 < LiBOB < LiBF4.

For the thermal stability of the electrolyte alone, Sino-era college and Kyushu university associated students carried out studies.

The electrolyte lithium salt is one mol·L - 1 LiPF6 and the natural solvent is a combination of different alkyl carbonate compounds. By means of measuring the heat launch fee, it becomes located that the ignition time primarily based on the EC /DEC combined device electrolyte became shorter. The temperature at which the one mol·L - 1LiPF6 /EC + DMC electrolyte well-known shows an exothermic top is 15 to twenty °C higher than that of the DEC-based electrolyte. The thermal balance of the electrolytebased totally on EC /DEC combined gadget is comparison with everyday hydrocarbons, the electrolyte has a higher heat of vaporization and lower combustion warmth. When the electrode fabric coexists with the electrolyte, the thermal stability of the coexisting machine is associated with the composition and mass ratio of the two components.

Tag: Electrolyte