Oxiranyl Ester Additive for Stable SEI in Li-Ion Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium ion batteries face challenges with low energy density, memory effect, and limited cycle stability due to irreversible lithium consumption in the formation of the solid electrolyte interface (SEI) during charging, which reduces the lifespan and efficiency of secondary electrochemical cells.
Innovation Solution
An electrolyte composition comprising aprotic organic solvents, conducting salts, and specific compounds of formula (I) that form a stable film on the anode, reducing internal resistance and enhancing cycle stability, is used in lithium ion batteries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electrolyte compositions are used, then the battery can operate, but irreversible lithium consumption occurs during SEI formation, reducing cycle stability and lifespan
Solution Approach 1:
The patent applies preliminary action by introducing compounds of formula (I) that pre-form a stable SEI film on the anode during initial cycles. This preliminary SEI formation prevents subsequent irreversible lithium consumption and protects the electrolyte from direct contact with the anode, thereby improving cycle stability and reducing lithium loss over time
Solution Approach 2:
The compounds of formula (I) act as intermediaries between the anode and the electrolyte. They form a protective SEI film that mediates the interaction between lithium ions and the anode surface, allowing reversible lithium insertion/extraction while preventing harmful direct reactions that would consume lithium irreversibly
2Reliability
If the SEI film is formed to protect the anode, then the electrolyte is protected from direct contact, but a certain amount of lithium is irreversibly consumed
Solution Approach 1:
The compounds of formula (I) perform preliminary SEI formation with minimal lithium consumption. The stable film formed during initial cycles creates a protective barrier that prevents further lithium loss, ensuring that the majority of lithium remains available for reversible cycling throughout the battery's operational life
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 proposed electrolyte composition improves the cycle stability and energy density of lithium ion batteries by minimizing irreversible lithium consumption and maintaining low internal resistance, leading to longer battery life and efficient energy storage.
Implementation Method 1
This film is formed by reductive decomposition of components of the electrolyte composition like solvents, e.g. carbonates, esters, and ethers, and conductive salts on the surface of the anode
Implementation Method 2
at least one conducting salt
Data Source
AI summary
The present invention relates to an electrolyte composition (A) containing (i) at least one aprotic organic solvent; (ii) at least one conducting salt; (iii) at least one compound of formula (I) and (iv) optionally at least one further additive.