Phenyl-Additive Electrolyte for Overcharge-Stable Lithium Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium secondary batteries face instability and performance degradation due to excess lithium intercalation and deintercalation under overcharge and overvoltage conditions, leading to safety concerns and reduced performance at various temperatures.
Innovation Solution
An electrolyte comprising a lithium salt, non-aqueous organic solvent, sulfone-based compound additive with a phenyl group, and silane-based compound additive, which forms protective films on electrodes to prevent electrolyte decomposition and enhance overcharge characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If various additives are added to the electrolyte to improve overcharge characteristics and safety, then battery safety is improved, but some of the performance of the lithium secondary battery is degraded
Solution Approach 1:
The patent changes the chemical parameters of the electrolyte by introducing a specific sulfone-based compound with phenyl group and silane-based compound with specific molecular structure. This compound combination creates a protective film on the electrode surface that improves overcharge characteristics while maintaining battery performance, resolving the contradiction between safety enhancement and performance preservation
Solution Approach 2:
The patent uses a composite electrolyte system combining sulfone-based compound additive and silane-based compound additive together with lithium salt and non-aqueous organic solvent. This composite approach creates synergistic effects where the combined additives form a more effective protective film than individual additives, improving overcharge characteristics without significantly degrading battery performance
2Quantity of substance
If excess lithium is deintercalated from positive electrode under overcharge and overvoltage environment, then battery capacity is increased, but both positive electrode and negative electrode become unstable
Solution Approach 1:
The sulfone-based compound and silane-based compound perform preliminary action by forming a protective film on the electrode surface before excessive lithium deintercalation occurs. This pre-formed film stabilizes the electrode structure during overcharge conditions, preventing electrode instability while allowing increased lithium capacity
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 improves safety and maintains performance at low (-10°C) and high (60°C) temperatures, while minimizing degradation and extending lifespan, by suppressing voltage increase and preventing electrolyte decomposition.
Implementation Method 1
a film is formed on the positive electrode under an overcharge and overvoltage environment so that a positive electrode is protected and the increase in the voltage is suppressed and thus the decomposition of electrolyte is suppressed
Data Source
AI summary
An electrolyte for a lithium secondary battery and a lithium secondary battery including the same are provided. The electrolyte for a lithium secondary battery may include: a lithium salt; a non-aqueous organic solvent; and a sulfone-based compound additive including at least one phenyl group and a silane-based compound additive including at least one phenyl group.