Secondary Battery Proton-Trapping Oxide for Hydrogen Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium nickel manganese oxide (LNMO) batteries generate hydrogen gas due to the decomposition of the nonaqueous electrolyte at the positive electrode, leading to swelling and reduced cycle life, as conventional measures like using cobalt-containing oxides fail to stabilize the crystal structure and prevent proton reduction.
Innovation Solution
Incorporating an alkali metal oxide that allows 50% or more of its alkali metal ions to be exchanged with protons, trapping generated protons before they reach the negative electrode, thereby preventing gas generation and enhancing cycle life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If cobalt-containing oxide is used to suppress hydrogen generation, then gas generation is reduced, but the crystal structure cannot be stabilized and proton reduction is prevented
Solution Approach 1:
The patent introduces an alkali metal oxide as an intermediary substance that mediates between the positive electrode and negative electrode. This alkali metal oxide specifically interacts with protons generated at the positive electrode, preventing their migration to the negative electrode where they would be reduced to hydrogen gas. The intermediary captures protons through ion exchange, thereby eliminating the harmful effect without compromising the electrochemical performance.
Solution Approach 2:
The patent converts the harmful protons generated during battery operation into a beneficial effect by having them trapped and exchanged by the alkali metal oxide. Instead of allowing protons to migrate and cause hydrogen gas generation, the system utilizes these protons to exchange with alkali metal ions in the oxide, effectively neutralizing the harmful effect while maintaining battery functionality.
2Power
If LNMO is used as positive electrode active material, then high discharge potential is achieved, but hydrogen gas is generated due to electrolyte decomposition
Solution Approach 1:
The alkali metal oxide serves as a mediator between the high-potential LNMO positive electrode and the electrolyte, intercepting protons generated by electrolyte decomposition before they can accumulate and form hydrogen gas. This intermediary layer allows the battery to operate at high discharge potentials while preventing the harmful side reaction.
3Duration of action of stationary object
If conventional measures are used to prevent gas generation, then cycle life is extended, but crystal structure stability is not achieved
Solution Approach 1:
The patent transforms the potentially harmful protons into a beneficial process by having them exchanged with alkali metal ions in the oxide structure. This ion exchange process stabilizes the crystal structure through the presence of alkali metal ions, while simultaneously preventing proton reduction to hydrogen gas, thereby achieving both crystal structure stability and extended cycle life.
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 secondary battery achieves excellent cycle life performance by effectively trapping protons, reducing gas generation, and maintaining the stability of the cobalt-containing oxide crystal structure even at high potentials.
Implementation Method 1
At least one of the positive electrode, the negative electrode, and the separator includes an alkali metal oxide, and 50% or more of alkali metal ions included in the alkali metal oxide are exchangeable with protons
Implementation Method 2
even when hydrogen gas is made into protons by the cobalt-containing oxide, protons are reduced again on the negative electrode to revert to hydrogen gas
Data Source
Figure 1~3
Figure 4
Figure 5
AI summary
According to one approach, provided is a secondary battery (100) including a positive electrode (5) containing a positive electrode active material, a negative electrode (3) containing a negative electrode active material, a separator (4) between the positive electrode (5) and the negative electrode (3), and an electrolyte. At least one of the positive electrode (5), the negative electrode (3), and the separator (4) contains an alkali metal oxide. 50% or more of alkali metal ions included in the alkali metal oxide is exchangeable with protons. Among the positive electrode active material and the negative electrode active material, a number of active material particles in contact with the alkali metal oxide is 10% or less of the whole.