SEI-Coated Carbon Positive Electrode for Dual-Intercalation Battery Stability
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Solution Overview
Problem
Dual intercalation non-aqueous electrolyte storage elements face issues with gas generation due to electrolyte decomposition at the electrode interface, which affects their stability and cycle life, especially during high-voltage charging and discharging.
Innovation Solution
A non-aqueous electrolyte storage element with a positive electrode featuring a carbon material having a three-dimensional network structure and a solid electrolyte interface (SEI) material on its surface, which suppresses electrolyte decomposition and gas generation without degrading the storage element's properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dual intercalation non-aqueous electrolyte storage element uses a carbonaceous material in the positive electrode to achieve high energy density and stable operation, then the storage element can operate stably at high voltage without elution of elements, but a large amount of gas is generated when charging and discharging cycles are repeated due to electrolyte decomposition at the electrode interface
Solution Approach 1:
The patent applies preliminary action by forming a solid electrolyte interface (SEI) film on the carbonaceous material surface before the storage element is put into service. This is achieved through preliminary charge treatment (charging to a predetermined potential value) and aging treatment (retaining at predetermined temperature), which intentionally reduction-decompose electrolyte components to create a protective SEI layer that prevents subsequent electrolyte decomposition and gas generation during normal operation
Solution Approach 2:
The patent uses the solid electrolyte interface (SEI) film as an intermediary layer between the carbonaceous material electrode and the electrolyte. This SEI film acts as a mediator that allows lithium ion conduction while blocking direct contact between the electrolyte and carbonaceous material, thereby preventing electrolyte decomposition and gas generation without compromising the electrochemical performance
2Object-affected harmful factors
If an SEI film is formed on the negative electrode through preliminary charge treatment and aging treatment to suppress electrolyte decomposition, then electrolyte decomposition is suppressed, but this approach does not address electrolyte decomposition at the positive electrode interface
Solution Approach 1:
The patent extends the SEI film formation approach from the traditional negative electrode application to the positive electrode as well. By applying the same preliminary charge treatment and aging treatment process to the carbonaceous material in the positive electrode, the invention achieves universal protection against electrolyte decomposition at both electrodes, making the solution broadly applicable to dual intercalation storage elements
3Reliability
If boron or boron-containing functional groups are introduced onto the negative electrode surface through plasma treatment to stabilize SEI generation, then SEI can be stably generated, but this method is complex and not applicable to the positive electrode
Solution Approach 1:
The patent replaces the complex plasma treatment method with a simpler, more economical approach using preliminary charge treatment and aging treatment. Instead of requiring expensive plasma equipment and boron-containing gases, the invention uses standard battery charging procedures and thermal aging processes that are already part of normal battery manufacturing and operation, achieving the same SEI stabilization effect with simpler, more accessible methods
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 solution effectively inhibits gas generation while maintaining high capacity and cycle life, ensuring stable operation without reducing the storage element's performance.
Implementation Method 1
a solid electrolyte interface (SEI) material on a surface of the carbon material... formation of the SEI suppresses decomposition of the electrolyte
Implementation Method 2
a positive electrode including a positive-electrode active material capable of inserting and eliminating anions
Implementation Method 3
a non-aqueous electrolyte... the SEI does not have electric conductivity but has lithium ion conductivity
Data Source
AI summary
To provide a non-aqueous electrolyte storage element including a positive electrode including a positive-electrode active material capable of inserting and eliminating anions, a negative electrode including a negative-electrode active material, and a non-aqueous electrolyte, wherein the positive-electrode active material includes a carbon material which has a plurality of pores constituting a three-dimensional network structure and has a solid electrolyte interface (SEI) material on a surface of the carbon material.