Cathode Additive for Lithium Secondary Battery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing cathode additives for lithium secondary batteries suffer from high irreversible capacity loss and residual by-products like lithium oxide, which cause oxygen gas generation and electrode gelation, limiting battery performance and capacity.
Innovation Solution
A cathode additive composed of a compound represented by the formula y(Li2Ni1-xMxO2)-z(Li6Co1-xMxO4), where M is an element like P, B, F, W, Ti, or Zr, with a molar ratio of y:z ranging from 2:1 to 30:1, is developed, reducing residual lithium oxide through additional calcination with a cobalt precursor, forming a single particulate complex with improved stability and capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If existing irreversible additives like Li2NiO2 are used to provide high irreversible capacity, then the anode irreversible capacity loss is compensated, but residual lithium oxide by-products remain that cause oxygen gas generation and electrode gelation
Solution Approach 1:
The harmful residual lithium oxide by-products are extracted and removed from the final additive product through a multi-step preparation process. The method separates the lithium oxide formation step from the final product, allowing it to be eliminated before the additive is applied to the cathode, thus preventing oxygen gas generation and electrode gelation while maintaining high irreversible capacity.
Solution Approach 2:
The preparation process utilizes parameter changes during calcination - specifically controlling temperature and atmosphere conditions - to transform the chemical state of lithium oxide. By adjusting calcination parameters, lithium oxide is converted into stable lithium carbonate or other non-harmful compounds, eliminating the harmful effects while preserving the irreversible capacity functionality of the additive.
2Quantity of substance
If non-carbon anode materials like silicon or tin are used to increase battery capacity, then the energy density is improved, but the initial efficiency is low causing large lithium consumption and irreversible capacity loss
Solution Approach 1:
The cathode additive is designed to self-regulate the lithium distribution in the battery. During the first charge-discharge cycle, the additive automatically provides the necessary lithium ions to compensate for the irreversible capacity loss of non-carbon anode materials, without requiring external intervention or additional lithium sources, thus improving initial efficiency while maintaining high capacity.
Solution Approach 2:
The additive employs composite material structure combining multiple metal oxides (such as nickel oxide, cobalt oxide, and manganese oxide) in specific ratios. This composite structure provides synergistic effects that enhance the irreversible capacity while improving the overall electrochemical performance and initial efficiency of the battery system using non-carbon anode materials.
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 new cathode additive significantly reduces oxygen gas generation and electrode gelation, enhancing battery capacity and stability by minimizing residual by-products, thereby improving the overall performance and lifespan of lithium secondary batteries.
Implementation Method 1
reducing residual lithium oxide through additional calcination with a cobalt precursor
Implementation Method 2
forming a single particulate complex with improved stability and capacity
Data Source
AI summary
The present disclosure relates to a cathode additive of a lithium secondary battery, and a method for preparing the same. The cathode additive exhibits high irreversible capacity, and may be effectively applied to a battery using an anode material having high energy density. In one embodiment, the cathode additive includes a compound represented by the following Chemical Formula 1:y(Li2Ni1-xMxO2)-z(Li6Co1-xMxO4) [Chemical Formula 1]