LNMO Electrode Cobalt Coating Gas Generation Prevention
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Solution Overview
Problem
Lithium nickel manganese oxide (LNMO) positive electrodes in non-aqueous electrolyte batteries generate gas during charge and discharge, leading to electrolyte decomposition and deterioration in input/output characteristics, especially under high-temperature conditions, and existing solid or gel electrolytes have lower Li conductivity than liquids, affecting battery performance.
Innovation Solution
An electrode composition featuring a current collector with an active material layer containing a cobalt-containing oxide and lithium nickel manganese oxide, where the cobalt-containing oxide is present in a ratio of 5 wt% to 40 wt% of the total weight, combined with a titanium-containing oxide negative electrode and a non-aqueous electrolyte, to prevent gas generation and maintain high operating voltage and input/output characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If lithium nickel manganese oxide (LNMO) positive electrodes are used to achieve high energy density, then energy density is improved, but gas generation occurs during charge and discharge leading to electrolyte decomposition
Solution Approach 1:
A coating layer comprising at least one of a metal oxide and a metal hydroxide is formed on the surface of the lithium nickel manganese oxide particles. This coating layer acts as an intermediary between the LNMO particles and the electrolyte, preventing direct harmful interactions that cause gas generation and electrolyte decomposition, while allowing the high energy density characteristics of LNMO to be maintained.
2Object-generated harmful factors
If solid or gel electrolytes are used to prevent gas generation, then gas generation is suppressed, but Li conductivity decreases compared to liquid electrolytes
Solution Approach 1:
Instead of changing the electrolyte type, a coating layer comprising at least one of a metal oxide and a metal hydroxide is applied to the LNMO particle surfaces. This coating acts as a protective intermediary that prevents gas generation and electrolyte decomposition reactions, allowing the use of liquid electrolytes with high Li conductivity while eliminating the harmful gas generation effect.
3Power
If lithium nickel manganese oxide electrodes operate under high-temperature conditions to maintain performance, then operating voltage and input/output characteristics are maintained, but gas generation and electrolyte decomposition are accelerated
Solution Approach 1:
The coating layer comprising metal oxide or metal hydroxide serves as a thermal and chemical barrier between the LNMO particles and the electrolyte. This intermediary protection becomes increasingly important under high-temperature conditions, preventing accelerated electrolyte decomposition and gas generation that would otherwise occur at elevated operating temperatures.
Solution Approach 2:
The coating layer changes the surface properties of the LNMO particles, creating a more stable interface that is less sensitive to temperature variations. This allows the electrode to maintain its input/output characteristics and operate at high temperatures without the same degree of electrolyte decomposition and gas generation that would occur in uncoated particles.
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 proposed electrode composition effectively prevents gas generation and electrolyte decomposition, enhancing cycle stability and input/output characteristics while maintaining high energy density and thermal stability, even under high-temperature conditions.
Implementation Method 1
Lithium nickel manganese oxide (LNMO) positive electrodes such as a LiNi0.5Mn1.5O4-containing positive electrode have a problem that those electrodes generate gas due to charge and discharge
Implementation Method 2
there is a problem that these electrolytes have a lower Li conductivity than liquids and causes deterioration in input/output characteristics
Data Source
AI summary
According to one embodiment, an electrode includes a current collector and an active material layer. The active material layer is disposed on at least one of faces of the current collector. The active material layer comprises active materials which include at least a cobalt-containing oxide and a lithium nickel manganese oxide. A ratio of a weight of the cobalt-containing oxide to a total of weights of the cobalt-containing oxide and the lithium nickel manganese oxide is 5 wt % or more and 40 wt % or less.