Sultone-Based Electrolyte for Silicon Anode Stability
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Solution Overview
Problem
Rechargeable lithium batteries with organic electrolytes face challenges in maintaining high temperature life-cycle characteristics due to side reactions between silicon-based negative active materials and conventional organic solvents, leading to deteriorated performance.
Innovation Solution
Incorporating a sultone-based compound, such as 1,3-propane sultone, in the electrolyte solution, along with a lithium salt and a specific organic solvent like ethyl acetate, to minimize side reactions and enhance the battery's life-cycle characteristics at both high and low temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If Si is used as negative active material to improve capacity and low temperature characteristics, then capacity and low temperature performance are improved, but side reaction between Si and conventional organic solvent occurs leading to deteriorated high temperature life-cycle characteristics
Solution Approach 1:
The patent introduces a sultone-based compound as an intermediary substance in the electrolyte that mediates between Si and conventional organic solvents. This additive forms a protective interface layer that prevents direct harmful interaction between Si and solvents while allowing beneficial electrochemical reactions to proceed, thus resolving the contradiction between capacity improvement and high temperature stability
Solution Approach 2:
The patent changes the chemical composition parameters of the electrolyte by incorporating sultone-based compounds (0.1-5 wt%) alongside conventional organic solvents. This parameter modification transforms the electrolyte's chemical properties to be compatible with Si, enabling both high capacity and improved high temperature life-cycle characteristics without sacrificing the benefits of Si as negative active material
2Use of energy by moving object
If high voltage is applied to rechargeable lithium battery to increase energy density, then energy density is improved, but life-cycle is sharply deteriorated
Solution Approach 1:
The sultone-based compound performs preliminary protective action by forming a stable interface layer on electrode surfaces before high voltage stress occurs. This pre-formed protective layer prevents subsequent degradation reactions that would normally occur under high voltage conditions, thereby maintaining both high energy density and extended life-cycle
3Power
If high voltage is applied to rechargeable lithium battery with increased resistance at low temperature, then energy output is maintained, but life-cycle is seriously deteriorated
Solution Approach 1:
The sultone-based compound acts as a chemical intermediary that facilitates efficient ion transport across electrode interfaces even under high voltage and low temperature conditions. This intermediary layer reduces interfacial resistance and prevents harmful side reactions, enabling the battery to maintain energy output while preserving life-cycle
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 electrolyte solution effectively improves the high temperature life-cycle characteristics of rechargeable lithium batteries by forming a protective layer that suppresses reactions between the silicon-based compound and the electrolyte, resulting in improved discharge capacity and capacity retention.
Implementation Method 1
the electrolyte solution effectively improves the high temperature life-cycle characteristics of rechargeable lithium batteries by forming a protective layer that suppresses reactions between the silicon-based compound and the electrolyte
Data Source
AI summary
An electrolyte solution for a rechargeable lithium battery that includes a lithium salt; a non-aqueous organic solvent including ethyl acetate; and an additive including a sultone-based compound, wherein the sultone-based compound is included in an amount ranging from 0.1 to 5 wt % based on the total amount of the electrolyte solution is provided.