Vanadium Ion Electrolyte Suppresses Gas Generation in Lithium-Ion Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium-ion secondary batteries using phosphate-based positive electrode materials face issues with low charging/discharging voltage, low energy density, and significant gas generation leading to swelling and shape stability degradation, which existing countermeasures have not adequately addressed.
Innovation Solution
A nonaqueous electrolyte containing 0.1 ppm to 20 ppm vanadium ions and a mixture of cyclic and chain carbonates is used, along with vanadium phosphate as the positive electrode active material, to suppress gas generation in lithium-ion secondary batteries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If phosphate-based positive electrode materials (LiCoPO4, LiNiPO4, LiVOPO4, Li3V2(PO4)3) are used to achieve high charging/discharging voltage (4V), then voltage is improved, but gas generation occurs leading to swelling and shape stability degradation
Solution Approach 1:
Vanadium ions (0.1-20 ppm) are introduced as an intermediary substance in the electrolyte that mediates the interaction between the phosphate-based positive electrode material and the electrolyte components. The vanadium ions suppress the oxidation decomposition reaction at the positive electrode surface, thereby preventing gas generation while maintaining the high voltage performance of the phosphate-based materials.
Solution Approach 2:
The concentration of vanadium ions in the electrolyte is precisely controlled within the range of 0.1-20 ppm to optimize the suppression effect on gas generation. Additionally, the electrolyte composition is adjusted by using a specific mixture of cyclic carbonate (15-30 vol%) and chain carbonate (70-85 vol%) to achieve the desired balance between voltage stability and gas suppression.
2Power
If conventional electrolytes are used with phosphate-based positive electrode materials, then high voltage (4V) is achieved, but oxidation decomposition occurs at the positive electrode surface causing gas generation
Solution Approach 1:
Vanadium ions serve as an intermediary that suppresses the oxidation decomposition reaction at the positive electrode surface. These ions interact with the electrolyte components near the electrode interface, preventing the oxidation of carbonate solvents while allowing the high voltage operation of phosphate-based materials.
Solution Approach 2:
The patent converts the potential harm of vanadium into a beneficial effect by carefully controlling its concentration at 0.1-20 ppm. At this optimized concentration, vanadium ions effectively suppress oxidation decomposition and gas generation, transforming what could be a contaminant into a protective agent that enhances battery performance and stability.
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 effectively reduces gas generation during charging and discharging, enhancing the stability and performance of lithium-ion secondary batteries by minimizing oxidation decomposition at the positive electrode surface.
Implementation Method 1
The proposed solution effectively reduces gas generation during charging and discharging, enhancing the stability and performance of lithium-ion secondary batteries by minimizing oxidation decomposition at the positive electrode surface
Implementation Method 2
a positive electrode which includes a positive electrode active material which intercalates and deintercalates lithium by oxide reduction reaction of transition metal, a negative electrode which can intercalate and deintercalate lithium
Implementation Method 3
a positive electrode which includes a positive electrode active material which intercalates and deintercalates lithium by oxide reduction reaction of transition metal
Data Source
AI summary
A nonaqueous electrolyte for a lithium-ion secondary battery containing 0.1 ppm to 20 ppm of vanadium in terms of vanadium ions, and containing cyclic carbonate and chain carbonate is used.