Boron Additive Electrolyte for High-Temperature Battery Stability
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Solution Overview
Problem
Conventional lithium ion batteries experience rapid performance degradation at higher temperatures, limiting their application in electric vehicles due to poor cycle properties and high interfacial impedance.
Innovation Solution
An electrolyte comprising a boron-based additive, specifically a compound represented by formula (I) or (II), is introduced to enhance the electrochemical stability and cycle life of lithium ion batteries, improving the performance of the positive electrode material under higher temperatures without increasing process complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lithium iron phosphate is used as positive electrode material to improve safety and cost, then safety and cost requirements are met, but performance degradation is quick under higher temperature
Solution Approach 1:
A boron-based additive compound is introduced as an intermediary substance in the electrolyte. This compound mediates the interaction between the lithium iron phosphate positive electrode and the electrolyte, forming a protective interface layer that prevents direct harmful reactions and reduces performance degradation at elevated temperatures.
Solution Approach 2:
The chemical composition and properties of the electrolyte are modified by adding the boron-based additive compound. This parameter change in the electrolyte composition alters the interfacial characteristics between the electrode and electrolyte, improving thermal stability and reducing degradation rate at higher temperatures.
2Power
If lithium ion batteries are designed for higher electric power to meet electric vehicle requirements, then electric power is improved, but cycle property and interfacial impedance become problematic at higher temperature
Solution Approach 1:
The boron-based additive acts as an intermediary that modifies the electrode-electrolyte interface, creating a more stable solid electrolyte interface (SEI) layer. This intermediate layer facilitates ion transport while maintaining structural integrity during cycling, thus improving cycle property at elevated temperatures.
Solution Approach 2:
The electrolyte system is transformed into a composite system by incorporating the boron-based additive compound alongside traditional lithium salts and solvents. This composite electrolyte formulation provides synergistic effects that enhance both power delivery and cycle stability at high temperatures.
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 boron-based additive significantly improves the cycle property and discharge capacity of lithium ion batteries at elevated temperatures, extending their lifespan and efficiency, making them more suitable for electric vehicle applications.
Implementation Method 1
The effect was that the conductivity of the electrolyte was enhanced by enhancement of dissociation of lithium salt
Implementation Method 2
the borane-based additive was involved to the formation of SEI films and contributed to dissolution of LiF during formation of SEI films
Data Source
AI summary
The present invention provides an electrolyte for electrochemical device and the electrochemical device thereof. The electrolyte comprises 9.95˜19.95 wt % of a salt; 80.0˜90.0 wt % of a non-aqueous solvent; 0.05˜10.00 wt % of an additive comprising a compound represented by below formula (I) or (II):wherein X1, R1, and R4˜R10 is defined as herein. Besides, the present invention also provides a method for enhancing cycle life of electrochemical device which accomplished by adding said additive to an electrolyte of electrochemical device.