Lithium-Ion Battery Electrolyte Additives for Wide-Temperature Performance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium-ion batteries face challenges in maintaining performance under extreme temperature conditions, as conventional electrolytes either deteriorate high-temperature performance or low-temperature performance, and existing additives either improve high-temperature performance at the expense of low-temperature performance or vice versa.
Innovation Solution
The use of a synergistic combination of specific additives, including sulfur-containing compounds and silyl-containing compounds, in the electrolyte to form protective films on electrodes, reducing impedance and enhancing the stability of the electrolyte at both high and low temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If film-forming additives are introduced to passivate the positive electrode, then high-temperature performance is improved, but low-temperature power performance deteriorates due to increased impedance
Solution Approach 1:
The patent employs a composite additive system combining multiple film-forming additives with different chemical structures and functions. This composite approach creates a multi-layered protective film on the positive electrode that balances high-temperature stability with low-temperature ionic conductivity, resolving the contradiction between temperature extremes.
Solution Approach 2:
The patent optimizes the concentration ratios and molecular weight parameters of the film-forming additives to achieve the desired film properties. By carefully controlling these parameters, the protective film provides adequate passivation at high temperatures while maintaining sufficient ionic transport at low temperatures.
2Temperature
If electrolyte solvent composition is optimized to reduce viscosity, then low-temperature performance is improved, but high-temperature gas production increases
Solution Approach 1:
The patent uses a composite solvent system combining multiple carbonate esters with different chain lengths and functional groups. This composite composition achieves optimal viscosity reduction for low-temperature performance while the synergistic interaction between components suppresses gas-generating side reactions at high temperatures.
Solution Approach 2:
The patent introduces film-forming additives as intermediaries that form protective layers on electrode surfaces. These intermediary films prevent direct contact between the low-viscosity solvent and electrode materials, thereby suppressing gas production at high temperatures while allowing the solvent to maintain its low-temperature fluidity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach results in improved high-temperature cycle performance, high-temperature storage performance, and reduced low-temperature DC impedance, effectively addressing the limitations of existing electrolytes by maintaining battery performance across a wide temperature range.
Implementation Method 1
the first additive and the second additive, wherein the first additive is selected from one or more of the following compounds: (Formula I) the second additive is selected from one or more of the following compounds: (Formula II) Under the synergistic effect of the first additive and the second additive, the lithium-ion battery can have better high-temperature cycle performance, high-temperature storage performance and lower low-temperature DC impedance
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
In the embodiments of the present application, an electrolyte, a lithium-ion battery comprising the electrolyte, a battery module, a battery pack, and a device are provided. The electrolyte in the embodiments of the present application comprises an organic solvent, an electrolyte lithium salt dissolved in the organic solvent, and an additive comprising a first additive and a second additive. The first additive is selected from one or more of the compounds represented by formula I, and the second additive is selected from one or more of the compounds represented by formula II. After applying the electrolyte of the present application to a lithium-ion battery, the lithium ion battery has a better cycle performance and storage performance at a high temperature, and lower direct-current impedance at a low temperature, such that the lithium ion battery has both a better high-temperature performance and a better low-temperature performance.