Lithium Battery Electrolyte Additives for High-Temperature Resistance Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rechargeable lithium batteries face challenges in achieving high output characteristics, high-temperature storage stability, and safety, particularly in terms of resistance increase and cycle-life performance.
Innovation Solution
An electrolyte composition for rechargeable lithium batteries is introduced, comprising a non-aqueous organic solvent, a lithium salt, and an additive mixture of a cesium salt compound and a phosphate-based or phosphite-based compound, which forms a film on electrodes to control lithium ion elution and prevent decomposition, thereby suppressing resistance increase and enhancing cycle-life characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electrolyte compositions are used, then basic battery operation is maintained, but resistance increases during high-temperature storage and cycle-life characteristics deteriorate
Solution Approach 1:
The patent applies preliminary action by introducing a cesium salt compound that reacts in advance during initial charging cycles to form a stable solid electrolyte interface (SEI) film on the electrode surface. This pre-formed protective film prevents subsequent decomposition reactions and resistance increase during high-temperature storage, addressing the technical contradiction before it manifests during normal operation.
Solution Approach 2:
The patent employs parameter changes by incorporating a specific concentration range of cesium salt compound (0.01-5 wt%) into the electrolyte composition. This parameter modification alters the electrochemical properties of the electrolyte, enabling the formation of a more stable interface film that resists degradation at high temperatures, thereby reducing resistance increase while maintaining reliable operation.
2Duration of action of moving object
If conventional electrolyte compositions are used, then basic battery operation is maintained, but cycle-life characteristics deteriorate
Solution Approach 1:
The cesium salt compound performs preliminary action by forming a stable protective film during initial cycles, which prevents electrode decomposition and electrolyte degradation throughout the battery's operational life. This pre-established protection mechanism extends cycle-life characteristics while maintaining performance stability over extended duration.
Solution Approach 2:
The patent applies composite materials by combining the cesium salt compound with conventional lithium salts (LiPF6, LiBF4, LiFSO3) and organic carbonates in a specific composition ratio. This composite electrolyte system synergistically enhances cycle-life characteristics and performance stability, overcoming the limitations of conventional single-component electrolytes.
3Reliability
If conventional electrolyte compositions are used, then basic safety is maintained, but high-temperature safety and output characteristics are insufficient
Solution Approach 1:
The cesium salt compound executes preliminary action by forming a thermally stable protective film on electrodes before high-temperature conditions cause degradation. This pre-formed barrier prevents harmful thermal runaway reactions and maintains safety under high-temperature stress, while the electrolyte composition preserves good output characteristics through maintained ionic conductivity.
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 composition effectively suppresses resistance increase during high-temperature storage and improves cycle-life and safety of rechargeable lithium batteries by forming a protective film on electrodes, leading to enhanced performance and stability.
Implementation Method 1
the additive is a composition including a first compound and a second compound... which forms a film on electrodes to control lithium ion elution and prevent decomposition
Implementation Method 2
The electrolyte serves as a medium for moving lithium ions between the negative electrode and the positive electrode
Data Source
AI summary
Provided are an electrolyte for a rechargeable lithium battery and a rechargeable lithium battery including the same, the electrolyte including a non-aqueous organic solvent, a lithium salt, and an additive, wherein the additive is a composition including a first compound and a second compound, the first compound is a cesium salt compound, and the second compound includes a composition including a second compound represented by Chemical Formula 1 or Chemical Formula 2.Details of the Chemical Formula 1 and Chemical Formula 2 are as described in the specification.