Multi-Component Electrolytes for Stable Silicon Li-Ion Cycling
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Solution Overview
Problem
Conventional battery electrodes, particularly those using silicon anodes, face challenges such as high cost, 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, enabling the use of silicon-dominant anodes with high voltage stability and reduced impedance growth.
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 changes and SEI instability cause limited cycle life
Solution Approach 1:
The patent modifies the chemical composition parameters of the electrolyte by incorporating specific additives (e.g., fluoroethylene carbonate at 5-30 wt%, lithium hexafluorophosphate at 0.5-2.0 M) to change the properties of the solid electrolyte interphase formed on silicon anodes, enabling stable cycling despite volume changes
Solution Approach 2:
The electrolyte composition acts as an intermediary between the silicon anode and the rest of the battery system, forming a stable protective interface that mediates the interaction and prevents direct harmful reactions between silicon and conventional electrolyte components
2Ease of manufacture
If conventional electrolyte compositions are used with silicon anodes, then manufacturing is simple, but thermal stability and interfacial compatibility are poor
Solution Approach 1:
The patent creates a composite electrolyte system by combining multiple components (cyclic carbonates, chain carbonates, fluorinated additives, lithium salts) that work synergistically to provide both thermal stability and compatibility with silicon anodes, while maintaining manufacturability through standard battery assembly processes
3Ease of manufacture
If silicon anodes are used to reduce cost, then material cost decreases, but impedance growth and gassing at high temperatures increase
Solution Approach 1:
The patent converts the potentially harmful interaction between silicon anodes and electrolyte into a beneficial stable interface by carefully selecting electrolyte additives that form protective films, thereby eliminating gassing and impedance growth issues while maintaining the cost advantages of silicon anodes
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 enhance the cycle life, reduce gassing at high temperatures, and maintain capacity retention, addressing the limitations of conventional silicon-based lithium-ion batteries by improving the stability and performance of silicon-dominant anodes.
Implementation Method 1
electrolyte compositions comprising multiple components like solvents, co-solvents, salts, and 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.