Boron-Modified Layered Oxide Cathode for Faster Initial Capacity
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Solution Overview
Problem
Li-rich nickel-manganese oxide requires activation through multiple charging and discharging cycles to achieve high capacity, necessitating improvements for faster and higher initial charge capacity.
Innovation Solution
Adding a boron-containing additive to a lithium composite oxide with a layered rock-salt structure, followed by heating and sintering at 850°C or higher, to create a positive electrode active substance with enhanced initial charge and discharge capacities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If Li-rich nickel-manganese oxide with layered structure is used to achieve high capacity, then the battery capacity is improved, but the initial charge capacity is small and requires multiple charging/discharging cycles for activation
Solution Approach 1:
The patent applies preliminary action by pre-modifying the lithium composite oxide with boron-containing additive before battery operation. This pre-treatment creates favorable conditions for subsequent charging/discharging reactions, eliminating the need for multiple activation cycles. The boron modification is performed during material synthesis, so the active material is already optimized before first use, resolving the contradiction between high capacity and activation time.
Solution Approach 2:
The patent changes the chemical composition parameters of the lithium composite oxide by introducing boron-containing additive in specific amounts (0.00075-0.2 equivalents per total Mn and Ni). This parameter modification alters the material's electrochemical properties, enabling high initial charge capacity without requiring multiple activation cycles. The controlled addition of boron changes the material structure to facilitate faster ion transport and reaction kinetics.
2Quantity of substance
If boron-containing additive is added to lithium composite oxide to improve initial charge capacity, then the initial charge capacity increases, but the manufacturing process becomes more complex
Solution Approach 1:
The patent merges the additive incorporation step with the existing sintering process. The boron-containing additive is mixed with the lithium composite oxide precursor and then sintered together in a single heating treatment at 850°C or higher. This combines material synthesis and additive integration into one step, avoiding separate modification steps and reducing manufacturing complexity while achieving high initial charge capacity.
Solution Approach 2:
The patent specifies precise parameter ranges for boron additive amount (0.00075-0.2 equivalents per total Mn and Ni) and sintering temperature (850°C or higher) to optimize the balance between performance improvement and process simplicity. By defining clear parameter windows, the patent makes the manufacturing process controllable and scalable without requiring complex process equipment or multiple steps.
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 modified positive electrode active substance achieves an initial charge capacity of 250 mAh/g and discharge capacity of 150 mAh/g, with stable capacity retention after multiple cycles, surpassing conventional technologies.
Implementation Method 1
performing heating and sintering at a temperature of 850° C. or higher
Data Source
AI summary
A positive electrode active substance having a layered rock-salt structure and having an initial charge capacity larger than that of a conventional technology is provided. The positive electrode active substance is obtained by adding an additive containing boron element to a lithium composite oxide having a layered rock-salt structure represented by Li2Mn1-xNixO3 (0≤x<1) or a precursor of the lithium composite oxide, and performing heating and sintering. The amount of boron is more than 0.00075 equivalents and 0.2 equivalents or less with respect to 1 equivalent of a total of Mn and Ni of the lithium composite oxide.