Lithium Battery Electrolyte Using Potassium Imide for Fast Charging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-rate charging of rechargeable lithium batteries leads to deteriorated lifecycle characteristics and increased resistance due to lithium dendrite formation on the negative electrode surface.
Innovation Solution
An electrolyte comprising a non-aqueous organic solvent, a lithium salt, and a potassium imide salt, specifically KFSI, KTFSI, or KFTFSI, is used to form a lithiophilic film on the negative electrode, reducing dendrite formation and improving charging performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If high-rate charging is performed, then charging speed is improved, but lifecycle characteristics deteriorate and resistance increases due to lithium dendrite formation
Solution Approach 1:
A potassium imide salt is introduced as an intermediary substance in the electrolyte composition (0.1-5 wt%). This additive acts as a mediator that modifies the electrolyte's interaction with the negative electrode surface, promoting the formation of a stable SEI film that prevents lithium dendrite formation while allowing high-rate charging to proceed without deteriorating lifecycle characteristics
Solution Approach 2:
The electrolyte composition parameters are modified by adding potassium imide salt to create a new chemical environment at the electrode interface. This parameter change in the electrolyte composition fundamentally alters the SEI formation process, enabling high-rate charging while maintaining battery reliability and preventing resistance increase
2Speed
If high-rate charging is performed, then charging speed is improved, but resistance increases due to lithium dendrite formation
Solution Approach 1:
The potassium imide salt serves as an intermediary that modifies the electrolyte-negative electrode interface. It mediates the interaction between lithium ions and the electrode surface, creating a protective SEI layer that prevents harmful resistance increase while enabling fast charging rates
Solution Approach 2:
The potassium imide salt converts the potentially harmful process of SEI formation into a beneficial protective mechanism. By controlling the decomposition and reformation of SEI at the electrode interface, the additive transforms what would normally be a source of resistance into a protective barrier that enables high-rate charging without harm
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 enhances high-rate charging performance while minimizing lifecycle deterioration and resistance increase, maintaining battery performance and safety.
Implementation Method 1
As the potassium imide salt is added to the electrolyte for a rechargeable lithium battery, a lithiophilic film can be formed on the surface of the negative electrode, and precipitates at the interface between the negative electrode and the electrolyte can be reduced or minimized
Data Source
Figure 1
AI summary
Examples of this disclosure relate to 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 a potassium imide salt.