Pre-Conditioned 3D Nanomesh Cathode for Lithium-Air Capacity Retention
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Solution Overview
Problem
Rechargeable lithium-air batteries face issues with low initial capacity, low efficiency, and poor capacity retention due to side reactions between oxygen and electrolyte components, leading to reduced performance and cyclability.
Innovation Solution
A method involving a pre-conditioned 3D nanomesh structure made of electronic conductive metal material, free of cathode active material, is introduced, which involves a pre-conditioning step to remove hydroxyl groups and inactive materials, and is used in a non-aqueous rechargeable metal-air battery to enhance initial capacity, rechargeability, and rate performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional air cathode with metal grid or carbon paper is used, then the battery structure is simple and easy to manufacture, but the initial capacity is low and the voltage gap between charge and discharge is large
Solution Approach 1:
The patent employs a 3D porous nanomesh structure made of conductive metal material with controlled pore sizes and high surface area. This porous architecture provides numerous active sites for oxygen reduction and evolution reactions, significantly increasing the initial capacity while maintaining structural integrity and electrical conductivity throughout the cathode
Solution Approach 2:
The patent creates a composite cathode structure by depositing conductive metal nanomesh onto a supportive substrate, combining the advantages of high surface area and porosity of the nanomesh with the mechanical strength and conductivity of the substrate, achieving both high initial capacity and good structural stability
2Device complexity
If a conventional air cathode is used, then the device complexity is low, but the capacity retention is poor and cyclability is limited
Solution Approach 1:
The 3D porous nanomesh structure facilitates efficient mass transport of oxygen and electrolyte species throughout the cathode, ensuring uniform reaction distribution and preventing localized degradation. The interconnected pore network allows for effective removal of reaction products, maintaining capacity retention over multiple cycles
Solution Approach 2:
The patent optimizes critical parameters including pore size distribution, surface area to volume ratio, and metal nanomesh thickness to enhance both capacity retention and cyclability. By carefully controlling these structural parameters, the cathode maintains high performance stability without requiring complex additional components
3Quantity of substance
If oxygen is supplied from the surrounding atmosphere, then the specific energy is very high, but side reactions occur between oxygen and electrolyte components
Solution Approach 1:
The conductive metal nanomesh acts as an intermediary between the oxygen from atmosphere and the electrolyte, providing a controlled interface for oxygen reduction reactions. This intermediary structure facilitates selective reaction pathways that minimize unwanted side reactions between oxygen and electrolyte components while maintaining high specific energy
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 pre-conditioned 3D nanomesh structure increases the initial capacity and rechargeability of metal-air batteries, improving the speed of discharge/charge and reducing the formation of undesirable side products, thereby enhancing the battery's overall performance.
Implementation Method 1
the lithium ion (Li+) is dissolved from the anode by electrochemical oxidation and transferred to the air cathode through an electrolyte
Implementation Method 2
a pre-conditioned 3D nanomesh structure made of electronic conductive metal material
Implementation Method 3
making a cathode comprising a 3D nanomesh structure made of electronic conductive metal material
Data Source
AI summary
A method (100) for making a non-aqueous rechargeable metal-air battery is provided. The method includes before and/or after inserting (108) a cathode in the battery, a pre-conditioning step (104, 106, 110) of a 3D nanomesh structure, so as to obtain a pre-conditioned 3D nanomesh structure, the pre-conditioned 3D nanomesh structure being free of cathode active material.A cathode to be inserted into a non-aqueous rechargeable metal-air battery is also provided. The cathode includes a pre-conditioned 3D nanomesh structure made of nanowires made of electronic conductive metal material, the pre-conditioned 3D nanomesh structure being free of cathode active material.A non-aqueous rechargeable metal-air battery including such a cathode is also provided.