Redox Polymer Electrode Additives for Fast-Charging Li-Ion Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inorganic-based lithium mixed electrode materials exhibit low charge transfer rates, leading to poor fast charging and discharging characteristics, and increased reactivity which can result in battery explosion and deterioration of cycle life characteristics, especially with high nickel content.
Innovation Solution
Incorporating a polymer additive with free radicals into the electrode, which undergoes oxidation-reduction reactions through ionic interactions, improving electrode stability and acting as a binder by increasing viscosity when dissolved in a solvent, thereby enhancing the electrochemical properties of secondary batteries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If inorganic-based lithium mixed electrode materials are used to increase capacity, then the battery capacity increases, but the charge transfer rate decreases leading to poor fast charging characteristics
Solution Approach 1:
The patent combines inorganic electrode materials with organic polymer materials containing free radicals to form a composite electrode structure. The inorganic material provides high capacity while the organic polymer component enhances charge transfer rate through its conductive properties and redox reactions, resolving the contradiction between capacity and charging speed
Solution Approach 2:
The patent introduces organic polymer materials with specific free radical content and molecular weight parameters to modify the electrode's electrical and chemical properties. By adjusting parameters such as polymer concentration, free radical density, and molecular structure, the charge transfer rate is enhanced without sacrificing the high capacity provided by inorganic materials
2Quantity of substance
If high nickel content is used to increase lithium ion capacity, then the battery capacity increases, but the reactivity increases leading to explosion risk and cycle life deterioration
Solution Approach 1:
The organic polymer material acts as an intermediary between the high nickel inorganic electrode material and the electrolyte. It forms a protective interface that moderates the reactivity of high nickel content, preventing direct harmful interactions while still allowing lithium ion transport, thus maintaining safety and cycle life despite high nickel content
Solution Approach 2:
The patent applies organic polymer coating specifically to the inorganic electrode material particles, creating a localized protective layer. This allows the bulk inorganic material to maintain high nickel content for capacity while the surface layer provides safety and stability, resolving the contradiction between capacity and reliability
3Device complexity
If conventional inorganic electrode materials are used, then the electrode structure is simple, but the fast charging and discharging characteristics are poor
Solution Approach 1:
The patent creates a composite electrode system combining inorganic and organic polymer materials. This composite structure enables fast charging and discharging characteristics through the synergistic effects of both materials while maintaining a relatively simple overall electrode architecture that can be manufactured using conventional processes
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 polymer additive increases the practical capacity and cycle life of secondary batteries by improving fast charging and discharging characteristics and maintaining high capacity even at high current densities, while reducing the risk of explosion and extending battery life.
Implementation Method 1
The organic polymer electrode additive of the present invention has free radicals. The organic polymer electrode additive of the present invention can increase the electrochemical reaction rate of a secondary battery because it undergoes an oxidation-reduction reaction through ionic interaction.
Implementation Method 2
The organic polymer electrode additive of the present invention can serve as a binder because it increases viscosity by dissolving in a solvent used for manufacturing an electrode.
Implementation Method 3
Because the organic polymer electrode additive of the present invention participates in an electrochemical reaction to store or release electrons, it can store ions such as sodium ion and lithium ion.
Data Source
AI summary
Inorganic-based lithium mixed electrode materials have a low charge transfer rate and thus have poor fast charging or discharging characteristics. Positive electrode active materials include LCO (lithium cobalt oxide, LiCoO2), NCM (nickel cobalt manganese, Li(NiCoMn)O2), NCA(nickel cobalt aluminum, Li(NiCoAl)O2), LMO(lithium manganese oxide, LiMn2O4), LFP(Lithium iron phosphate, LiFePO4), etc. High nickel technology is attracting attention because if nickel is used a lot, the capacity of lithium ions can be increased. However, as the content of nickel increases, the reactivity increases, resulting in a risk of explosion of the battery and deterioration in cycle life characteristics. As the negative active material, carbon, transition metal oxide, nickel metal, silicon-nickel alloy, and the like may be used. As the carbon, natural graphite, artificial graphite, soft carbon, hard carbon, etc. can be used. As the transition metal oxide, Co3O4, CoO, FeO, NiO, and the like can be used.The present invention adds a polymer additive containing free radicals in the molecular structure to the electrode to solve the problems of the existing secondary battery. The polymer additive contains free radicals and undergoes an oxidation-reduction reaction through ionic interactions. When this polymer additive is included in the electrode, the fast charging and fast discharging characteristics are improved, and the stability of the electrode is improved. When the stability of the electrode is improved, the cycle life characteristics of the electrode are improved. Because the polymer additive participates in the electrochemical reaction, it increases the practical capacity of nickel. When dissolved in a solvent, the polymer additive can increase the viscosity and act as a binder.