Silver-Tin Coated Silicon Anode Slurry for Fast-Charging Li-Ion Batteries
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Solution Overview
Problem
Silicon anode materials for lithium ion batteries are reactive and require careful handling in non-oxidizing environments, limiting their use in developing batteries with larger capacity and higher charging rates.
Innovation Solution
Coating silicon particles with silver and/or tin nanoparticles within specific size ranges, combined with conductive additives and binders, to form a passivated anode slurry that can be processed in water-based environments, reducing reactivity and enhancing conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If silicon particles are used as anode active material, then battery capacity is increased, but reactivity in oxidizing environment worsens
Solution Approach 1:
The patent applies composite materials by coating silicon particles with a dual-layer structure: an inner aluminum oxide layer and an outer carbon layer. This composite structure combines the high capacity benefits of silicon with the protective properties of aluminum oxide and carbon, creating a material that maintains electrochemical performance while resisting oxidation in the electrolyte environment.
Solution Approach 2:
The patent creates an inert protective environment around silicon particles by forming an aluminum oxide coating that acts as a barrier to oxygen and electrolyte contact. This inert layer prevents direct interaction between the reactive silicon and the oxidizing environment, allowing silicon to function effectively in battery electrodes without degradation.
2Reliability
If silicon particles are coated with silver and/or tin particles, then conductivity is improved, but manufacturing complexity increases
Solution Approach 1:
The patent merges multiple functions into a single coating process by simultaneously forming aluminum oxide and carbon layers in one heat treatment step, and then adding silver or tin particles in the same or subsequent processing steps. This integration reduces the number of separate manufacturing operations compared to applying each coating layer independently.
Solution Approach 2:
The patent utilizes parameter changes by controlling heat treatment temperature and atmosphere to transform the coating structure. By adjusting these parameters, the aluminum oxide and carbon layers form through phase changes and chemical reactions during a single heat treatment process, simplifying manufacturing while achieving the desired conductive and protective properties.
3Length of moving object
If silicon particles are milled in organic solvent, then particle size is reduced, but processing time increases
Solution Approach 1:
The patent maintains continuity of useful action by performing milling in an organic solvent without requiring intermediate drying or transfer steps. The slurry can be directly used for subsequent coating and heat treatment processes, eliminating time-consuming intermediate steps and maintaining continuous processing while achieving the desired particle size reduction.
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 solution enables the production of anodes with improved conductivity and extended cycling lifetime, allowing for high-performance fast-charging lithium ion batteries with high power and energy density, while simplifying the production process and reducing silicon reactivity.
Implementation Method 1
coating silicon particles with silver and/or tin nanoparticles within specific size ranges, combined with conductive additives and binders, to form a passivated anode slurry
Implementation Method 2
enhancing conductivity
Implementation Method 3
the NPs comprise at least one of: metalloid oxide NPs, metalloid salt NPs, Sb and/or Cu salt NPs, Sn, Sb, Cu, SnSb alloy and/or SnCu alloy NPs, metallic Ag, Au, Pb and/or Ge NPs
Data Source
AI summary
Methods of preparing Si-based anode slurries and anode made thereof are provided. Methods comprise coating silicon particles within a size range of 300-700 nm by silver and/or tin particles within a size range of 20-500 nm, mixing the coated silicon particles with conductive additives and binders in a solvent to form anode slurry, and preparing an anode from the anode slurry. Alternatively or complementarily, silicon particles may be milled in an organic solvent, and, in the same organic solvent, coating agent(s), conductive additive(s) and binder(s) may be added to the milled silicon particles—to form the Si-based anode slurry. Alternatively or complementarily, milled silicon particles may be mixed, in a first organic solvent, with coating agent(s), conductive additive(s) and binder(s)—to form the Si-based anode slurry. Disclosed methods simplify the anode production process and provide equivalent or superior anodes.