Multi-Component Electrolytes for Stable Si-Anode Li-Ion Cycling
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Solution Overview
Problem
Conventional battery electrodes, particularly those using silicon anodes, face challenges such as high cost, complexity, inefficiency, and limited cycle life due to large volume changes and unstable solid electrolyte interphase formation, which affect the energy density and safety of lithium-ion batteries.
Innovation Solution
The development of electrolyte compositions comprising multiple components like solvents, co-solvents, salts, and additives, which improve thermal stability and interfacial compatibility, and the use of silicon-dominant anodes with conductive additives and carbonized polymers to enhance electrical conductivity and mechanical robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If silicon-dominant anodes are used to increase energy density, then capacity is improved, but volume expansion and mechanical degradation occur during cycling
Solution Approach 1:
The patent employs a flexible polymer binder matrix that can accommodate the volume expansion of silicon particles during lithiation. The polymer network acts as a flexible shell that maintains structural integrity while allowing silicon to expand and contract, preventing mechanical degradation and maintaining electrode robustness over multiple cycles.
Solution Approach 2:
The patent creates a composite material system where silicon particles are embedded within a polymer binder matrix. This composite structure combines the high capacity of silicon with the mechanical flexibility and electrochemical stability of the polymer, achieving both high energy density and mechanical robustness simultaneously.
2Ease of manufacture
If conventional electrolyte compositions are used, then manufacturing is simple, but thermal stability and interfacial compatibility are insufficient
Solution Approach 1:
The patent modifies the electrolyte composition by adjusting the ratios of cyclic carbonate to linear carbonate solvents and selecting specific lithium salt combinations. These parameter changes enhance thermal stability and interfacial compatibility with silicon anodes while maintaining manufacturability through standard battery assembly processes.
Solution Approach 2:
The patent uses a composite electrolyte system combining multiple carbonate solvents and lithium salts in specific proportions. This composite electrolyte formulation provides both thermal stability and good interfacial compatibility, resolving the contradiction between reliability and ease of manufacture.
3Quantity of substance
If silicon anodes undergo large volume changes, then capacity is improved, but solid electrolyte interphase stability deteriorates
Solution Approach 1:
The flexible polymer binder creates a stable interface between the silicon anode and electrolyte that can accommodate volume changes. This flexible interface layer maintains solid electrolyte interphase stability even as silicon expands and contracts during cycling, preventing continuous SEI formation and capacity loss.
Solution Approach 2:
The patent adjusts electrolyte composition parameters including solvent ratios and additive concentrations to promote formation of a stable solid electrolyte interphase on silicon surfaces. These parameter changes ensure SEI stability despite the large volume changes experienced by silicon anodes during lithiation and delithiation.
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
These electrolyte compositions and anode materials improve the cycle life, reduce impedance, and enhance the energy density and safety of lithium-ion batteries, making them suitable for high-energy applications like electric vehicles and energy storage systems.
Implementation Method 1
electrolyte compositions comprising two or more components such as solvents, co-solvents, salts and/or additives
Implementation Method 2
unstable solid electrolyte interphase formation
Data Source
AI summary
Electrolyte formulations for energy storage devices are disclosed. The energy storage device comprises a first electrode and a second electrode, where one or both of the first electrode and the second electrode is a Si-based electrode, a separator between the first electrode and the second electrode, and an electrolyte composition. Electrolyte formulations as described herein are electrolyte compositions comprising two or more components such as solvents, co-solvents, salts and/or additives. In some embodiments, three or more, four or more, five or more, six or more, seven or more, or eight or more components are included in the electrolyte composition.