Boron-Modified Layered Cathode Material for Higher Initial Charge
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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 in 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, to enhance the initial charge capacity.
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 surface of Li-rich nickel-manganese oxide with boron-containing compounds before battery assembly. This surface modification is performed in advance during material preparation, creating a boron-containing layer that prepares the material for immediate high-capacity operation without requiring extended activation cycles. The boron modification is done beforehand to enable the material to achieve target capacity from the first charge cycle.
2Use of energy by moving object
If Li-rich nickel-manganese oxide is used to achieve high capacity, then the energy density is improved, but the initial charge capacity needs to be activated through repeated charging and discharging
Solution Approach 1:
The patent applies parameter changes by modifying the surface chemical composition of Li-rich nickel-manganese oxide through boron addition. By changing the surface parameters (compositional parameters) to include boron-containing species, the material's electrochemical properties are altered to enable immediate high charge capacity from the first cycle, while preserving the bulk properties that provide high energy density.
3Shape
If conventional Li-rich nickel-manganese oxide is used, then the layered rock-salt structure is maintained, but the initial charge capacity is insufficient
Solution Approach 1:
The patent applies local quality by creating a differentiated structure where the bulk material maintains the layered rock-salt structure while the surface region acquires different properties through boron modification. The surface layer with boron-containing compounds provides enhanced initial charge capacity, while the interior bulk material preserves the original layered structure that enables high theoretical capacity. This local differentiation resolves the contradiction between structural integrity and initial performance.
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 exhibits an initial charge capacity exceeding conventional technologies, achieving higher and more stable charge and discharge capacities across cycles.
Implementation Method 1
adding an additive containing boron element to a lithium composite oxide or a precursor of the lithium composite oxide such that the amount of boron is more than 0.00075 equivalents and 0.2 equivalents or less with respect to 1 equivalent of the total of Mn and Ni of the lithium composite oxide
Data Source
Figure 1
Figure 2A~2B
AI summary
The present invention provides a positive electrode active substance having a layered rock-salt structure and having an initial charge capacity larger than that of a conventional technology. 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 such that an 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, and performing heating and sintering.