Composite Anode Active Material for Lithium Battery
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Solution Overview
Problem
Lithium batteries for electric vehicles face challenges in achieving high-discharge capacity, long-term usability, and charge/discharge efficiency due to limitations in carbonaceous materials and metal anode active materials, which suffer from low capacity, poor high-rate characteristics, and rapid degradation.
Innovation Solution
A composite anode active material is developed, comprising porous particles with composite nanostructures that include a crystalline carbon nano-sheet and metal nanowires arranged on the substrate, which are integrated to form one-body structures, enhancing conductivity and resistance to volumetric changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If carbonaceous materials are used as anode active material, then the anode exhibits good stability and low volumetric change, but the battery capacity is limited due to the porous structure of carbon
Solution Approach 1:
The patent creates a composite anode material combining carbonaceous materials with metals that are alloyable with lithium (such as silicon, tin, aluminum). This composite structure allows the carbon component to provide stability and volumetric resistance while the metal component contributes high electrical capacity, thereby resolving the contradiction between stability and battery capacity.
2Quantity of substance
If metals that are alloyable with lithium are used as anode active material, then the electrical capacity is higher compared with carbonaceous materials, but the charge/discharge efficiency is low and lifetime characteristics are poor
Solution Approach 1:
The patent forms a composite where metals alloyable with lithium are combined with carbonaceous materials. The carbon component provides structural stability and good charge/discharge efficiency, while the metal component delivers high electrical capacity. This composite approach resolves the contradiction by allowing each material to contribute its advantageous properties while mitigating its weaknesses.
Solution Approach 2:
The patent creates a composite structure where different materials are distributed in specific configurations - carbonaceous materials providing stable frameworks and metal particles dispersed within, each performing their optimal functions locally. This local quality differentiation allows the anode to simultaneously achieve high capacity from metal regions and good efficiency from carbon regions.
3Quantity of substance
If metals such as tin are used as anode active material, then the electrical capacity is improved, but degradation occurs with repeated charging and discharging due to agglomeration and breakage of metal particles
Solution Approach 1:
The patent combines tin or other alloyable metals with carbonaceous materials to form a composite anode. The carbon matrix provides structural support that prevents metal particle agglomeration and breakage during cycling, while the metal particles maintain their high capacity function. This resolves the contradiction between capacity and lifetime stability.
Solution Approach 2:
The carbonaceous material acts as a protective cushioning matrix that anticipates and prevents the degradation of metal particles during repeated charging and discharging. This pre-established protective structure absorbs the mechanical stress and prevents particle breakage before degradation can occur.
Data Source
AI summary
In an aspect, a composite anode active material including: a porous particles, said porous particles including: a plurality of composite nanostructures; and a first carbonaceous material binding the composite nanostructures, wherein the porous particles have pores within the particle, and wherein the composite nanostructures include a crystalline second carbonaceous material substrate including at least one carbon nano-sheet, and a plurality of metal nanowires arranged at intervals on the crystalline second carbonaceous material substrate is disclosed.