Lithium Battery Electrolyte Additive for Cathode Interface Stability
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Solution Overview
Problem
Lithium secondary batteries experience degradation in stability and cycle life due to side reactions between the cathode active material and electrolyte during repeated charging and discharging, particularly at low and high temperatures.
Innovation Solution
An electrolyte for lithium secondary batteries comprising an additive with a specific structure, an organic solvent, and a lithium salt, which forms a uniform solid electrolyte interphase (SEI) on the electrode surface, suppressing side reactions and enhancing ionic conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electrolytes are used in lithium secondary batteries, then the batteries can operate with basic performance, but the stability and cycle life degrade due to side reactions between cathode active material and electrolyte at low and high temperatures
Solution Approach 1:
The patent introduces a membrane coating layer comprising a specific compound (Formula 1) as an intermediary between the cathode active material and the electrolyte. This coating layer acts as a protective barrier that prevents direct contact and side reactions between the cathode material and electrolyte, particularly at low and high temperatures, thereby improving stability and cycle life without compromising basic battery operation
Solution Approach 2:
The patent modifies the interface parameters between cathode and electrolyte by applying a coating layer with specific chemical composition and structure. The coating layer changes the surface properties, wettability, and chemical reactivity parameters of the cathode material surface, creating an optimized interface that reduces harmful side reactions while maintaining ionic conductivity
2Adaptability or versatility
If the battery operates at low temperatures, then the battery can function in cold environments, but side reactions increase causing degradation in stability and cycle life
Solution Approach 1:
The membrane coating layer serves as a temperature-adaptive intermediary that provides enhanced protection at low temperatures. The specific compound structure (Formula 1) with aryl group and substituents creates a coating that maintains its protective function and prevents side reactions even in cold environments where conventional electrolytes would otherwise promote degradation
Solution Approach 2:
The patent applies local quality enhancement by creating a specialized coating layer with distinct chemical properties at the cathode-electrolyte interface. This localized modification provides temperature-specific protection where it is most needed, with the coating layer's composition and structure optimized to prevent low-temperature side reactions while allowing normal operation
3Power
If the battery operates at high temperatures, then the battery can deliver high power, but side reactions between cathode active material and electrolyte increase causing stability degradation
Solution Approach 1:
The membrane coating layer acts as a thermal-stable intermediary that protects the cathode material from thermal degradation and electrolyte decomposition at high temperatures. The coating layer maintains its structural integrity and protective function under elevated temperature conditions, preventing side reactions that would otherwise occur during high-power operation
Solution Approach 2:
The patent applies preliminary protection by pre-forming a stable coating layer on the cathode material before battery operation. This pre-established protective barrier is designed to withstand high-temperature conditions and prevent degradation reactions before they can occur, allowing the battery to safely deliver high power without stability loss
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 improves low-temperature performance, high-temperature storage properties, and cycle life of lithium secondary batteries by stabilizing the electrode interface and preventing decomposition, thereby reducing gas generation and battery thickness increase.
Implementation Method 1
forms a uniform solid electrolyte interphase (SEI) on the electrode surface, suppressing side reactions and enhancing ionic conductivity
Implementation Method 2
stabilizing the electrode interface and preventing decomposition
Data Source
AI summary
An electrolyte for a lithium secondary battery according to exemplary embodiments includes an additive including a compound having a structure represented by Formula 1, an organic solvent and a lithium salt. The electrolyte for a lithium secondary battery according to exemplary embodiments may form a uniform and stable solid electrolyte interphase (SEI) with high ionic conductivity on the electrode surface. Accordingly, a lithium secondary battery including the electrolyte for a lithium secondary battery may exhibit improved low-temperature performance and high-temperature stability.