Rechargeable Lithium Battery Electrolyte for High-Temperature Cycle Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rechargeable lithium batteries face challenges in maintaining stable charge/discharge characteristics and cycle-life performance, particularly at high temperatures, with significant gas generation during storage.
Innovation Solution
Incorporating a specific electrolyte solution comprising a first isocyanurate-based compound and a second compound with a -PO2F functional group, along with a cobalt-free lithium nickel composite oxide, to form stable solid electrolyte interface films on electrodes, reducing gas generation and enhancing performance at high temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional electrolyte solutions are used in rechargeable lithium batteries, then the batteries can operate at high temperatures, but gas generation increases significantly during storage at high temperatures
Solution Approach 1:
The patent introduces a mediator substance (specific electrolyte additive containing phosphorus and nitrogen atoms) that acts as an intermediary between the electrode and the electrolyte solution. This mediator forms a protective interface layer that prevents direct harmful interactions, thereby suppressing gas generation while maintaining high temperature operation capability.
Solution Approach 2:
The patent changes the chemical composition parameters of the electrolyte solution by incorporating specific compounds with phosphorus and nitrogen atoms. This parameter change modifies the electrochemical properties of the electrolyte, reducing its tendency to generate gas at high temperatures while preserving its ionic conductivity and electrochemical stability.
2Productivity
If conventional electrolyte solutions are used, then the batteries can be charged and discharged, but charge/discharge characteristics deteriorate when stored at high temperatures
Solution Approach 1:
The patent applies preliminary action by having the electrolyte additive form a stable protective film on the electrode surface before high temperature storage begins. This pre-formed protective layer prevents subsequent degradation reactions, preserving charge/discharge characteristics even after prolonged high temperature storage.
Solution Approach 2:
The patent uses composite materials by combining multiple electrolyte components with specific phosphorus and nitrogen-containing compounds. This composite electrolyte formulation creates synergistic effects that enhance both charge/discharge performance and high temperature stability, preventing characteristic deterioration.
3Ease of operation
If conventional electrolyte solutions are used, then the batteries can operate at room temperature, but cycle-life characteristics deteriorate at both room and high temperatures
Solution Approach 1:
The phosphorus and nitrogen-containing compounds act as intermediary substances that form stable protective interfaces on electrode surfaces. This intermediary layer prevents direct contact between the electrolyte and electrode, reducing degradation reactions that would otherwise occur during cycling, thereby extending cycle life at both room and high temperatures.
Solution Approach 2:
The patent employs small amounts of sacrificial electrolyte additives that preferentially react to form stable protective films. These additives act as disposable protective agents that consume themselves to create long-lasting protective interfaces, extending the overall battery cycle life.
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 solution improves charge/discharge characteristics and cycle-life performance at both room and high temperatures while significantly reducing gas generation, ensuring stable battery operation under high voltage/high temperature conditions.
Implementation Method 1
Incorporating a specific electrolyte solution comprising a first isocyanurate-based compound and a second compound with a -PO2F functional group, along with a cobalt-free lithium nickel composite oxide, to form stable solid electrolyte interface films on electrodes
Implementation Method 2
electrical energy is produced by oxidation and reduction reactions when lithium ions are intercalated/deintercalated at the positive and negative electrodes
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A rechargeable lithium battery is provided. The rechargeable lithium battery includes a positive electrode active material; a negative electrode including a negative electrode active material; an electrolyte solution for a rechargeable lithium battery including a non-aqueous organic solvent, a lithium salt, and an additive, wherein the additive includes a first compound represented by Chemical Formula 1 and a second compound represented by Chemical Formula 2, and the positive electrode active material includes lithium nickel composite oxide represented by Chemical Formula 3.