Encapsulated Cathode Lithium Additive for Battery Gas Suppression
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Solution Overview
Problem
Existing cathode lithium-supplementing additives in lithium-ion batteries cause increased gas production during the formation stage, leading to safety issues and unsatisfactory performance, with no clear mechanism understood for gas production and existing solutions affecting battery properties negatively.
Innovation Solution
A composite cathode lithium-supplementing additive with a core and a functional encapsulation layer containing an oxygen-consuming agent, which inhibits gas production by removing active oxygen and isolates the core from the ambient environment, ensuring stability and lithium-supplementing effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cathode lithium-supplementing additives are used to compensate for irreversible capacity loss, then initial coulombic efficiency is improved, but gas production increases causing safety issues
Solution Approach 1:
The additive is segmented into distinct functional modules: a lithium-supplementing core component and a protective coating layer. This segmentation allows the core to provide lithium ions for compensating capacity loss while the coating layer independently manages gas production suppression, resolving the contradiction between improving initial coulombic efficiency and reducing gas generation.
Solution Approach 2:
A protective coating layer acts as an intermediary between the lithium-supplementing additive and the battery environment. This intermediary layer suppresses gas production while allowing the core additive to function, thus mediating the conflict between lithium supplementation and gas control.
2Object-generated harmful factors
If traditional protective films are formed using anhydride compounds or cyclic esters to inhibit gas production, then gas generation is reduced, but ionic conductivity deteriorates and impedance increases
Solution Approach 1:
The invention changes the chemical composition parameters of the protective film by using specific coating materials that maintain both gas suppression capability and ionic conductivity. This parameter optimization resolves the contradiction between reducing gas production and maintaining electrical performance.
Solution Approach 2:
The protective coating is designed as a composite material structure combining multiple components with complementary functions. This composite approach allows simultaneous achievement of gas production suppression and maintenance of ionic conductivity, overcoming the limitations of single-material protective films.
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
The additive effectively inhibits gas production, improves safety, enhances initial coulombic efficiency, and maintains electrochemical performance by providing abundant lithium and stable core protection.
Implementation Method 1
the functional encapsulation layer contains an oxygen-consuming agent... effectively remove active oxygen... inhibit the active oxygen from inducing gas production reaction
Data Source
AI summary
A composite cathode lithium-supplementing additive and preparation method and application thereof are provided. The composite cathode lithium-supplementing additive of the present application includes a core and a functional encapsulation layer covering the core, the core includes a cathode lithium-supplementing material, and the functional encapsulation layer contains an oxygen-consuming agent. The composite cathode lithium-supplementing additive of the present application can effectively remove active oxygen, inhibit the active oxygen from inducing gas production reaction, thereby inhibiting the gas production of the battery containing the composite cathode lithium-supplementing additive of the present application during the charging and discharging process, and effectively improving the safety of the battery. In addition, the preparation method of the composite cathode lithium-supplementing additive can ensure that the structure and electrochemical performance of the prepared composite cathode lithium-supplementing additive are stable, the efficiency is high, and production cost is saved.