Lithium Ion Battery Positive Electrode Multi-Electron Capacity
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Solution Overview
Problem
Current lithium ion secondary batteries face a capacity saturation point, limiting further increases in energy storage despite efforts to optimize charging voltage and surface structure of lithium-containing transition metal compounds like LixMeO2.
Innovation Solution
Incorporating a lithium-containing transition metal compound with a specific molar ratio of lithium to transition metal M (2.7 to 3.3) and a mass ratio of 0.8 or more in the positive electrode, belonging to space group Fd3-m, which enables multi-electron participation in charge/discharge reactions, along with a non-aqueous electrolyte containing fluorine solvents for enhanced stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the charging voltage is increased and the surface structure is optimized to increase the capacity of LixMeO2, then the capacity can be improved to some extent, but the amount of capacity increase is reaching the saturation point and cannot be further improved
Solution Approach 1:
The patent changes the fundamental parameters of the positive electrode active material by introducing a lithium-containing transition metal compound with specific space group Fd3-m and controlled Li/M ratio (2.7-3.3), replacing conventional LixMeO2 materials. This parameter change enables multi-electron participation in charge/discharge reactions, achieving high capacity of 450 mAh/g or more while avoiding the saturation limit encountered with traditional materials
Solution Approach 2:
The patent employs a composite material system consisting of lithium-containing transition metal compound (space group Fd3-m) combined with specific non-aqueous electrolyte components. This composite approach integrates the high-capacity positive electrode material with optimized electrolyte formulation to achieve synergistic effects, enabling stable high-voltage operation and efficient charge/discharge reactions that neither component could achieve alone
2Quantity of substance
If a lithium-containing transition metal compound with specific composition ratios is used to achieve high capacity, then the battery capacity increases, but the manufacturing precision requirements increase
Solution Approach 1:
The patent establishes specific parameter ranges for the lithium-containing transition metal compound (space group Fd3-m, Li/M ratio of 2.7-3.3) that balance high capacity achievement with manufacturability. These defined parameters provide clear manufacturing targets while ensuring the material delivers 450 mAh/g or more capacity, resolving the tension between performance and manufacturing precision
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
This configuration results in a lithium ion secondary battery with a high capacity, maintaining stability even at high charging voltages and ensuring efficient charge/discharge reactions, thereby overcoming the capacity limitations of existing batteries.
Implementation Method 1
a lithium-containing transition metal compound that belongs to space group Fd3-m and that contains lithium and transition metal M... which enables multi-electron participation in charge/discharge reactions
Implementation Method 2
a non-aqueous electrolyte containing fluorine solvents for enhanced stability
Data Source
AI summary
A lithium ion secondary battery includes a positive electrode; a negative electrode; a separator disposed between the positive electrode and the negative electrode; and a non-aqueous electrolyte, wherein the positive electrode contains, as a positive electrode active material, a lithium-containing transition metal compound that belongs to space group Fd3-m and that contains lithium and transition metal M (M represents Mo, or Mo and at least one selected from the group consisting of Mn, Co, Ni, W, and V), a molar ratio of the lithium to the transition metal M is 2.7 or more and 3.3 or less, and a ratio of a mass of the lithium-containing transition metal compound to a total mass of the positive electrode active material in the positive electrode is 0.8 or more.