Silicon Anode Oxide-Carbon Coating for Cycle Life and Low Swelling
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Solution Overview
Problem
Lithium ion batteries face challenges in achieving high capacity, long service life, and swelling resistance due to the degradation of silicon-based anode materials during cycling.
Innovation Solution
An anode material comprising a silicon composite substrate coated with an oxide MeOy layer containing a carbon material, where Me includes Al, Si, Ti, Mn, V, Cr, or Zr, and y is between 0.5 to 3, is prepared by forming a mixed solution of silicon oxide, carbon, and an oxide precursor, followed by sintering to create a protective layer that enhances lithium ion conductivity and reduces swelling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If silicon-based anode materials are used to achieve high capacity, then the battery capacity increases, but the service life decreases due to degradation during cycling
Solution Approach 1:
The patent applies composite materials by creating a core-shell structure where silicon particles are coated with an oxide layer (MeOy) containing carbon material. The silicon core provides high capacity while the oxide-c carbon shell maintains structural stability during cycling, preventing degradation and extending service life. This composite structure resolves the contradiction between achieving high capacity and maintaining reliability.
2Quantity of substance
If silicon-based anode materials are used to achieve high capacity, then the battery capacity increases, but swelling resistance decreases during cycling
Solution Approach 1:
The patent employs a flexible protective shell approach by coating silicon particles with an oxide layer (MeOy) that contains carbon material. This shell acts as a flexible constraint that accommodates the volume expansion of silicon during lithium insertion while preventing excessive swelling that would lead to structural collapse. The carbon component within the oxide layer enhances this swelling resistance, allowing the anode to maintain high capacity without excessive swelling.
3Reliability
If a protective oxide layer is added to improve cycle performance, then service life increases, but device complexity increases
Solution Approach 1:
The patent merges multiple functions into a single protective layer. The oxide layer (MeOy) simultaneously provides structural protection, contains carbon material for enhanced conductivity and stability, and prevents electrolyte decomposition. This consolidation of multiple protective functions into one integrated layer improves cycle performance without proportionally increasing device complexity, as the layer serves multiple purposes simultaneously.
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 anode material exhibits improved cycle performance and lower swelling rates, resulting in better rate performance of the lithium ion battery.
Implementation Method 1
an oxide MeOy layer, the oxide MeOy layer coats at least a portion of the silicon composite substrate
Implementation Method 2
sintering the powder at about 200 to 1000° C. for about 0.5 to 25 hr, to obtain silicon compound SiOx particles with an oxide MeOy layer on the surface
Implementation Method 3
Lithium ion batteries have occupied a leading position in the market due to their outstanding advantages
Data Source
AI summary
An anode material includes silicon-containing particles including a silicon composite substrate and an oxide MeOy layer, wherein the oxide MeOy layer is coated on at least a portion of the silicon composite substrate, wherein Me includes at least one of Al, Si, Ti, Mn, V, Cr, Co or Zr, and y is 0.5 to 3; and wherein the oxide MeOy layer includes a carbon material. The anode material has good cycle performance, and the battery prepared from the anode material has better rate performance and lower swelling rate.