Silicon Composite Anode Coating for Low-Swelling Li-Ion Cells
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Solution Overview
Problem
Existing lithium-ion batteries face challenges in achieving high energy density, long cycle life, and low swelling rates due to non-uniform particle size distribution and inadequate protection of the anode material.
Innovation Solution
The anode material comprises a silicon composite substrate with a specific particle size distribution (0.1≤Dn10/Dv50≤0.6) and a coating of oxide MeOy layer containing carbon, which enhances cycle performance and conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silicon composite substrate with narrow particle size distribution is used, then cycle performance is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent applies parameter changes by optimizing the particle size distribution parameters (Dv50 between 2.5-15 μm and Dn10/Dv50 ratio between 0.1-0.6) of the silicon composite substrate. By controlling these specific parameters, the invention achieves improved cycle performance while providing clear manufacturing targets that balance precision requirements with manufacturability.
2Object-affected harmful factors
If anode material is protected with oxide coating, then swelling rate is reduced, but conductivity may decrease
Solution Approach 1:
The patent employs composite materials by combining the silicon composite substrate with an oxide coating layer containing carbon. This composite structure provides both the protection needed to reduce swelling and the conductivity enhancement from carbon, simultaneously addressing both requirements rather than treating them as conflicting.
Solution Approach 2:
The oxide coating layer containing carbon acts as an intermediary between the silicon substrate and the electrolyte. It protects the silicon from direct contact with the electrolyte (reducing swelling) while the carbon component ensures adequate conductivity is maintained, mediating between protection and conductivity needs.
3Reliability
If graphite is used as anode active material, then safety is improved, but energy density decreases
Solution Approach 1:
The patent uses composite materials by combining graphite with silicon oxide (SiOx where 0.6≤x≤1.5). Graphite provides the safety and structural stability, while silicon oxide contributes to higher capacity. The composite structure allows both materials to work synergistically, achieving both safety and high energy density.
Data Source
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AI summary
The present application relates to an anode material, an electrochemical device and an electronic device comprising the anode material. The anode material of the present application comprises a silicon composite substrate, wherein the Dv50 of the silicon composite substrate is from 2.5 µm to 15 µm, and the particle size distribution of the silicon composite substrate meets 0.1≤Dn10/Dv50≤0.6. The anode material of the present application has good cycle performance, and the battery prepared with the anode material has good rate performance and lower swelling rate.