Anode Active Material Composite for Battery Stability
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Solution Overview
Problem
Existing lithium secondary battery anodes have low energy density, leading to manufacturing yield issues and deteriorated lifespan and resistance characteristics when attempting to produce high-capacity, high-density anodes.
Innovation Solution
An anode comprising a first anode active material with higher hardness and a second anode active material of lower hardness, mixed in a specific volume ratio, to decrease volumetric expansion and increase adhesion strength between the anode mixture and current collector, thereby enhancing structural stability and performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high-capacity and high-density anode is manufactured by the same method as existing low energy density anode, then capacity and density are improved, but manufacturing yield deteriorates and lifespan and resistance characteristics are deteriorated
Solution Approach 1:
The patent applies composite materials by combining two different anode active materials with distinct hardness characteristics. The first anode active material has higher hardness while the second has lower hardness, creating a composite structure that leverages the strengths of each material to achieve both high capacity/density and improved reliability in terms of lifespan and resistance characteristics.
Solution Approach 2:
The patent implements local quality by creating regions with different hardness properties within the anode structure. By distributing the two anode active materials with different hardness values throughout the composite, the anode achieves localized mechanical properties that collectively improve both performance and reliability without uniform compromise.
2Quantity of substance
If high-capacity and high-density anode is manufactured by the same method as existing low energy density anode, then capacity and density are improved, but manufacturing yield is not obtained at the same level
Solution Approach 1:
The composite material approach enables improved manufacturing yield by creating a more robust anode structure that is less prone to defects during manufacturing. The combination of hard and soft materials provides structural integrity while accommodating manufacturing variations, thereby maintaining high capacity and density without sacrificing yield.
Solution Approach 2:
The patent applies parameter changes by modifying the physical and chemical parameters of the anode active materials, specifically their hardness characteristics. By selecting materials with appropriate hardness values and combining them in specific ratios, the invention optimizes both the capacity/density parameters and the manufacturing yield parameter simultaneously.
3Strength
If two anode active materials with different hardness are mixed in specific volume ratio, then adhesion strength between anode mixture and current collector is increased, but structural complexity increases
Solution Approach 1:
The patent uses composite materials to enhance adhesion strength between the anode mixture and current collector. The lower hardness material in the composite acts as an adhesive phase that improves bonding to the current collector, while the higher hardness material provides structural support. This composite approach increases adhesion strength without requiring complex multi-layer structures or additional adhesive components.
Solution Approach 2:
The invention merges the functions of structural support and adhesion into a single composite anode active material mixture. By combining materials with different hardness properties, the system integrates the structural role of hard materials with the adhesive role of soft materials, eliminating the need for separate structural and adhesive layers, thus reducing overall structural complexity while maintaining high adhesion strength.
Data Source
AI summary
Provided is an anode for a secondary battery including: a first anode active material; and a second anode active material having relatively lower hardness than that of the first anode active material. The first anode active material and the second anode active material satisfy Relational Formula 1 0.167<RB/RA<1, and have a volume ratio of 1:0.5˜2. In Relational Formula 1, RA is an average particle size of the first anode active material, and RB is an average particle size of the second anode active material.