Partial Cathode Coating for Lower Resistance Build-Up
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Solution Overview
Problem
Existing lithium ion batteries face issues with undesired reactions on the surface of cathode active materials, leading to efficiency losses due to particle agglomeration and resistance build-up during cycling.
Innovation Solution
A process for partially coating electrode active materials with metal alkoxides or metal halides, followed by moisture treatment, to achieve a non-homogeneous coating of at least 80% of the particles, reducing chemical reactivity and minimizing resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the electrode active material is coated to protect the surface and reduce reactions, then the reliability is improved, but the device complexity increases
Solution Approach 1:
The patent changes the chemical parameters of the coating process by using metal alkoxides or metal halides that react with moisture to form protective oxide layers. By controlling the moisture content in the range of 50 to 1,000 ppm and repeating the coating-moisture treatment sequence 2 to 10 times, the process achieves reliable surface protection with controlled complexity through parameter optimization
Solution Approach 2:
The patent introduces moisture as an intermediary substance that facilitates the reaction between metal alkoxides/halides and the electrode surface. The moisture acts as a mediator to form hydroxyl groups and oxide layers, enabling the coating process to proceed effectively while maintaining manageable process complexity
2Reliability
If a coating is applied to protect the surface, then the reliability is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The patent applies partial coating rather than attempting complete uniform coverage. By treating the material with metal alkoxides/halides and moisture in repeated cycles (2 to 10 times), the process achieves sufficient surface protection on the particles that matter most, accepting that not every surface area needs identical coverage. This partial action approach reduces the stringency of manufacturing precision requirements while maintaining reliable surface protection
Solution Approach 2:
The patent allows different regions of the particle surface to have different coating characteristics. The coating process creates localized protective layers where the metal alkoxides or halides react with moisture to form oxide or hydroxyl groups, with at least 80% of particles being coated. This local quality approach ensures protection where needed without requiring uniform precision across the entire batch
3Reliability
If the coating thickness is increased to improve protection, then the reliability is improved, but the productivity decreases
Solution Approach 1:
The patent uses periodic action by repeating the sequence of coating with metal alkoxides/halides followed by moisture treatment 2 to 10 times. Each cycle builds up the protective layer incrementally, allowing the formation of sufficiently thick coating (6 to 15 nm or 16 to 50 nm) while maintaining productivity through efficient cyclic processing rather than requiring excessively long continuous treatment
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 process results in a coated electrode active material with reduced resistance build-up during repeated cycling, enhancing the efficiency and discharge performance of lithium ion batteries.
Implementation Method 1
treating the material obtained in step (b) with moisture
Implementation Method 2
treating said electrode active material with a metal alkoxide or metal halide or metal amide or alkyl metal compound
Implementation Method 3
performing a post-treatment by heating the material obtained after the last step (d) at a temperature from 200 to 400° C.
Data Source
AI summary
Process for making a partially coated electrode active material wherein said process comprises the following steps: (a) Providing an electrode active material according to general formula Li1+x, TM1+XO2, wherein TM is a combination of Ni, Co and, optionally, Mn, and, optionally, at least one metal selected from Al, Ti and Zr, and x is in the range of from zero to 0.2, wherein at least 60 mole-% of the transition metal of TM is Ni, and wherein said electrode active material has a residual moisture content in the range of from 50 to 1,000 ppm, (b) treating said electrode active material with a metal alkoxide or metal halide or metal amide or alkyl metal compound, (c) treating the material obtained in step (b) with moisture, (d) repeating the sequence of steps (b) and (c) twice to ten times, (e) performing a post-treatment by heating the material obtained after the last step (d) at a temperature from 200 to 400° C.