Electrolyte Additives for High Voltage Cycle Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current lithium-ion battery electrolyte systems face deficiencies in cycle performance and storage performance, particularly at high voltage and high temperature, leading to increased resistance and capacity degradation.
Innovation Solution
Incorporating a multi-cyano six-membered N-heterocyclic compound and a sulfonate compound as additives in the electrolyte to form a stable SEI film, reducing gas production and side reactions, and using a halogenated cyclic carbonate to enhance the electrochemical performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electrolyte systems are used, then basic battery operation is maintained, but cycle performance and storage performance deteriorate at high voltage and high temperature
Solution Approach 1:
The patent applies preliminary action by introducing additives (sulfonate compound and multi-cyano compound) that proactively form protective films on electrode surfaces before degradation can occur. These additives preferentially react with electrode surfaces at high temperature and voltage conditions to create stable SEI films, preventing subsequent electrolyte decomposition and capacity fade, thus resolving the contradiction between maintaining reliability under high temperature stress.
Solution Approach 2:
The patent uses additives as intermediary substances that mediate between the electrolyte and electrode surfaces. The sulfonate and multi-cyano compounds act as intermediaries by forming interfacial protective layers that prevent direct harmful interactions between the electrolyte and electrodes under high voltage and temperature conditions, thereby improving cycle performance without sacrificing operational capability.
2Reliability
If conventional electrolyte systems are used, then basic battery operation is maintained, but storage performance deteriorates under high voltage and high temperature conditions
Solution Approach 1:
The patent applies preliminary anti-action by introducing additives that preemptively counteract oxidation reactions. The sulfonate and multi-cyano compounds preferentially oxidize themselves or form protective films that prevent the electrolyte from oxidizing during storage at high voltage and temperature, thereby maintaining storage performance while allowing normal battery operation.
3Reliability
If conventional electrolyte systems are used, then battery operation is maintained, but gas production increases leading to swelling
Solution Approach 1:
The additives serve as intermediary substances that mediate between the electrolyte and electrode surfaces to prevent gas-generating side reactions. By forming stable protective films, these intermediaries prevent direct contact between the electrolyte and electrode surfaces that would otherwise produce gas, thus maintaining battery operation while reducing gas production and swelling.
4Use of energy by moving object
If conventional electrolyte systems are used, then basic electrochemical function is maintained, but side reactions increase at high voltage
Solution Approach 1:
The patent applies preliminary action by introducing additives that proactively form protective films on electrode surfaces before high-voltage operation begins. These pre-formed films prevent subsequent side reactions that would consume energy and reduce efficiency, thereby maintaining electrochemical function while minimizing energy loss to parasitic reactions.
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 solution significantly improves cycle performance and storage performance at high temperature and high voltage, reducing reductive decomposition and side reactions, thereby extending battery life and maintaining capacity retention.
Implementation Method 1
the additives can be adsorbed on catalytically active sites of the graphite surface to form a more stable SEI film
Implementation Method 2
inhibit the positive electrode material from oxidizing the electrolyte
Implementation Method 3
reducing reductive decomposition and side reactions
Data Source
Figure 1~3
AI summary
The present disclosure relates to the field of energy storage materials, and specifically, to an electrolyte and an electrochemical device. The electrolyte includes an additive A, an additive B and an additive C, the additive A is selected from a group consisting of multi-cyano six-membered N-heterocyclic compounds represented by Formula I-1, Formula I-2 and Formula I-3, and combinations thereof, the additive B is at least one sulfonate compound, and the additive C is at least one halogenated cyclic carbonate compound. The electrochemical device includes the above electrolyte. The electrolyte of the present disclosure can effectively passivate surface activity of the positive electrode material, inhibit oxidation of the electrolyte, and effectively reduce gas production of the battery, meanwhile the electrolyte can be adsorbed on catalytically active sites of the graphite surface to form a stable SEI film, thereby effectively reducing side reactions. The electrochemical device using the electrolyte of the present disclosure has good high temperature and high voltage cycle performance and storage performance.