Fluorine-Containing Battery Electrode Stabilizes Thermal Reactions
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Solution Overview
Problem
Conventional lithium-ion batteries face safety issues due to thermal reactions between the electrolyte solution and positive electrode active materials, leading to instability and reduced capacity.
Innovation Solution
A battery design incorporating a positive electrode active material with a compound of the form LixMeyOαFβ, where Me is a specific set of elements and x, y, α, β satisfy certain conditions, and an electrolyte solution containing hydrofluoroethers, phosphazenes, or perfluoropolyethers, which stabilizes the fluorine-containing skeleton and prevents thermal reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electrolyte solutions are used with positive electrode active materials, then battery capacity can be achieved, but thermal reactions occur leading to safety issues and reduced stability
Solution Approach 1:
The patent introduces a fluorine-containing compound as an intermediary substance that mediates between the electrolyte solution and the positive electrode active material. This compound forms a protective interface layer that prevents direct contact and thermal reactions between the electrolyte and the positive electrode material, thereby eliminating the harmful thermal reactions while maintaining battery safety and stability
Solution Approach 2:
The patent uses a composite positive electrode active material containing both the fluorine-containing compound and conventional positive electrode materials. This composite structure allows the fluorine-containing compound to provide protective functions while the conventional materials maintain electrochemical activity, resolving the contradiction between achieving battery capacity and preventing thermal reactions
2Quantity of substance
If Li extraction is increased to improve capacity, then battery capacity increases, but structural integrity of the positive electrode active material deteriorates
Solution Approach 1:
The patent applies beforehand cushioning by introducing the fluorine-containing compound that forms a protective layer on the positive electrode active material before Li extraction occurs. This protective layer acts as a cushion that prevents structural collapse and degradation during high Li extraction processes, allowing increased capacity while maintaining structural integrity
Solution Approach 2:
The patent changes the chemical composition parameters of the positive electrode active material by incorporating fluorine-containing compounds with specific formulas (LxMyOαFβ). This parameter change in composition enhances the structural stability of the material, enabling it to withstand higher Li extraction levels while maintaining integrity, thus resolving the contradiction between capacity and structural 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
This configuration enhances the safety and capacity of lithium-ion batteries by reducing oxygen release from the positive electrode active material and stabilizing the fluorine-containing skeleton, maintaining structural integrity even with high Li extraction, resulting in a high-capacity and high-safety battery.
Implementation Method 1
an electrolyte solution containing hydrofluoroethers, phosphazenes, or perfluoropolyethers, which stabilizes the fluorine-containing skeleton and prevents thermal reactions
Data Source
AI summary
Provided is a battery including: a positive electrode containing a positive electrode active material; a negative electrode; and an electrolyte solution containing a nonaqueous solvent. The positive electrode active material contains a compound represented by composition formula (1) below and having a crystal structure belonging to space group FM3-M: LixMeyOαFβ. (1) Here, Me is one or two or more elements selected from the group consisting of Mn, Co, Ni, Fe, Al, B, Ce, Si, Zr, Nb, Pr, Ti, W, Ge, Mo, Sn, Bi, Cu, Mg, Ca, Ba, Sr, Y, Zn, Ga, Er, La, Sm, Yb, V, and C. x, y, α, and β satisfy the following conditions: 1.7≤x≤2.2, 0.8≤y≤1.3, 1≤α≤2.5, and 0.5≤β≤2, respectively. The nonaqueous solvent includes at least one solvent selected from hydrofluoroethers, phosphazenes, phosphates, and perfluoropolyethers.