Composite Electrolyte Layer for LNMO Battery Gas Suppression
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Solution Overview
Problem
Nonaqueous electrolyte secondary batteries using lithium nickel manganese oxide (LNMO) face issues with gas generation and battery swelling due to decomposition of organic solvents in the electrolyte, which existing coatings fail to adequately address without compromising lithium-ion conductivity and rate characteristics.
Innovation Solution
An electrode group configuration with a composite electrolyte layer of specific density (1.0 g/cc to 2.2 g/cc) and lithium-ion conductivity, containing a solid electrolyte and inorganic compounds like alumina, is used to suppress decomposition product movement and maintain ion conductivity between the positive and negative electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the positive electrode active material is coated entirely with lithium-conductive glass to prevent contact with organic solvent, then gas generation is suppressed, but lithium-ion conductivity decreases and rate characteristics deteriorate
Solution Approach 1:
The patent applies local quality by creating a composite coating with distinct functional zones: a lithium-conductive glass layer (5-20 nm thick) that provides gas suppression at the interface with organic solvent, and a porous inorganic compound layer (5-50 nm thick) containing alumina that maintains lithium-ion conductivity. Each layer performs its specific function locally without compromising the other, resolving the contradiction between gas suppression and rate characteristics.
Solution Approach 2:
The patent uses composite materials by combining lithium-conductive glass (such as Li2SiO3, Li2SiO2O, or Li4SiO4) with porous inorganic compounds (such as alumina, silica, or titania) in a layered structure. This composite approach allows the system to simultaneously achieve the gas suppression properties of the glass coating and the high lithium-ion conductivity of the porous inorganic layer, directly resolving the technical contradiction.
2Object-generated harmful factors
If a coating is applied to prevent organic solvent decomposition, then gas generation is reduced, but the complexity of the electrode structure increases
Solution Approach 1:
The patent employs thin film technology by creating a dual-layer coating structure where the total thickness is controlled at 5-100 nm. The lithium-conductive glass layer (5-20 nm) and porous inorganic compound layer (5-50 nm) are both in the thin film regime, providing protective functionality while minimizing structural complexity and maintaining electrode flexibility.
Solution Approach 2:
The patent applies parameter changes by precisely controlling the thickness parameters of each coating layer (lithium-conductive glass: 5-20 nm, porous inorganic compound: 5-50 nm) and their compositional ratios. By optimizing these parameters, the coating achieves effective gas suppression while maintaining simplicity in the overall electrode structure and processing.
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 effectively suppresses gas generation, improves battery life, and maintains high rate performance by controlling the movement of decomposition products and retaining nonaqueous electrolyte, while ensuring appropriate ion conductivity.
Implementation Method 1
an electrode group is provided. The electrode group includes a positive electrode that includes a lithium composite oxide LiMxMn2-xO4 (0
Implementation Method 2
containing a solid electrolyte and inorganic compounds like alumina, is used to suppress decomposition product movement and maintain ion conductivity between the positive and negative electrodes
Data Source
AI summary
According to one embodiment, an electrode group is provided. The electrode group includes a positive electrode that includes a lithium composite oxide LiMxMn2-xO4 (0<x≤0.5, M is at least one selected from a group consisting of Ni, Cr, Fe, Cu, Co, Mg, and Mo) as a positive electrode active material, a negative electrode that includes a negative electrode active material, a composite electrolyte layer that includes at least one of a solid electrolyte and an inorganic compound containing alumina, and a separator. The composite electrolyte layer and the separator are arranged between the positive electrode and the negative electrode. A density of the composite electrolyte layer is in the range of 1.0 g/cc and 2.2 g/cc.