Lithium Nickel Oxide Additive Composition for Low-Gelation Cathodes
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Solution Overview
Problem
Existing methods for preparing positive electrode additives for lithium secondary batteries result in high irreversible capacity loss, gelation issues during manufacturing, and excessive gas generation due to unreacted residues and by-products.
Innovation Solution
A method involving the mixing of lithium, nickel raw materials, and optionally an element M, followed by heat-treatment to produce a lithium nickel oxide with a specific chemical formula, Li2Ni1-xMxO2, where M is selected from transition metals, amphoteric elements, P, F, and B, and LiOH is used in a controlled amount to reduce by-products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lithium nickel-based oxide is produced by reacting nickel oxide with excess lithium oxide, then the positive electrode material can provide lithium ion source and compensate irreversible capacity loss, but the reaction yield is low and unreacted residues or by-products remain
Solution Approach 1:
The patent changes the chemical composition parameters by introducing element M (transition metal, amphoteric element, P, F, or B) into the lithium nickel oxide structure to form Li2Ni1-xMxO2. This compositional modification improves reaction completeness and reduces unreacted residues while maintaining the lithium ion source function for compensating irreversible capacity loss.
Solution Approach 2:
The patent creates a composite oxide material Li2Ni1-xMxO2 by combining lithium nickel oxide with element M. This composite structure enhances the reaction yield and reduces by-products compared to conventional lithium nickel oxide, while preserving the electrochemical activity needed for capacity compensation.
2Reliability
If unreacted residues or by-products such as Li2O, NiO, LiOH, and Li2CO3 remain in the irreversible additive, then gas generation occurs during initial cycle decomposition, but the presence of these residues also causes gelation during electrode composition preparation
Solution Approach 1:
The patent modifies the chemical composition by incorporating element M to reduce the formation of LiOH and other gelation-causing by-products. The controlled composition of Li2Ni1-xMxO2 minimizes unwanted side reactions during electrode preparation, eliminating gelation issues while maintaining battery cycle lifespan through effective capacity compensation.
3Reliability
If LiOH reacts with binder component to increase viscosity of electrode composition, then uniform application of electrode composition becomes difficult, but the reaction also deteriorates battery characteristics
Solution Approach 1:
The patent changes the chemical parameters by using LiOH in a controlled amount (3-25 wt% of total lithium raw material) and incorporating element M to minimize harmful reactions. This composition control prevents excessive viscosity increase and maintains electrode composition uniformity while preserving essential battery characteristics through the lithium ion source function.
4Reliability
If free LiOH and free Li from LiOH decomposition deteriorate cycle efficiency of positive electrode, then capacity of irreversible additive is reduced, but lithium oxide or nickel oxide hardly exhibits basic capacity
Solution Approach 1:
The patent creates the composite material Li2Ni1-xMxO2 that balances the competing requirements. The element M incorporation stabilizes the structure to reduce free LiOH formation, improving cycle efficiency, while the overall composition maintains sufficient lithium content and electrochemical activity to provide the necessary irreversible capacity for compensating negative electrode losses.
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 approach results in a positive electrode additive with enhanced irreversible capacity, reduced gelation during manufacturing, and decreased gas generation during battery operation, leading to improved electrochemical and lifespan characteristics.
Implementation Method 1
heat-treating them to produce a lithium nickel oxide of Chemical Formula 1
Data Source
AI summary
The present disclosure relates to a method for preparing a positive electrode additive for a lithium secondary battery having a high irreversible capacity and being capable of preventing gelation and reducing gas generation, and a positive electrode additive prepared thereby. The method for preparing the positive electrode additive includes the steps of: mixing a lithium raw material, a nickel raw material and, optionally, a raw material containing an element M, and then heat-treating the mixture, thereby preparing a predetermined lithium nickel oxide, wherein the lithium raw material includes Li2O and LiOH, and the LiOH is used in an amount of 5 to 10% by weight with respect to the total weight of the lithium raw material.