Uniform Metal-Semiconductor Alloy Anode for Silicon Batteries
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Solution Overview
Problem
Nonaqueous electrolyte secondary batteries, such as lithium-ion batteries, face issues with capacity degradation due to cycling-induced exfoliation and poor conductivity in anode materials, particularly silicon anodes, which result in reduced cycle life and energy density.
Innovation Solution
A uniform metal-semiconductor alloy layer is formed on anode materials through a displacement plating process followed by annealing, enhancing conductivity and reducing volume expansion without substantial efficiency loss, using a metal ion solution and a dissolution component to deposit metal on semiconductor-containing anodes, such as nickel on silicon.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If silicon anode material is used to achieve high capacity, then energy density is improved, but electrical conductivity deteriorates and capacity degradation increases due to poor conductivity and cycling-induced exfoliation
Solution Approach 1:
The patent applies composite materials by combining silicon anode material with a metal-semiconductor alloy coating layer. This composite structure maintains the high capacity benefits of silicon while the metal-semiconductor alloy layer provides improved electrical conductivity and structural stability during cycling, preventing exfoliation and extending cycle life.
Solution Approach 2:
The patent changes the physical and chemical parameters of the anode material surface by applying a metal-semiconductor alloy coating. This coating modifies the electrical conductivity parameter and mechanical properties of the silicon surface, enabling it to withstand volume expansion and contraction during lithium insertion/extraction cycles without degrading.
2Quantity of substance
If silicon anode material is used to achieve high capacity, then energy density is improved, but electrical conductivity deteriorates
Solution Approach 1:
The patent creates a composite structure where silicon particles are coated with a metal-semiconductor alloy layer. The metal component (such as nickel, copper, or cobalt) provides high electrical conductivity, while the semiconductor component maintains compatibility with lithium insertion. This composite coating resolves the conductivity problem while preserving the high energy density of silicon.
Solution Approach 2:
The patent applies local quality by treating only the surface of the silicon particles with a metal-semiconductor alloy coating. The core silicon material retains its high capacity properties, while the surface coating provides the necessary electrical conductivity. This localized modification optimizes both properties without compromising the overall energy density.
3Loss of energy
If metal coating is applied to improve conductivity, then electrical conductivity is improved, but manufacturing uniformity deteriorates due to non-uniform deposition
Solution Approach 1:
The patent replaces conventional mechanical or physical deposition methods with a chemical displacement plating process. In this process, metal ions in solution are reduced and deposited on the silicon surface through a chemical reaction, resulting in uniform and controlled coating thickness. This chemical approach provides better manufacturing precision compared to physical deposition methods.
Solution Approach 2:
The patent controls the deposition process by adjusting chemical parameters such as solution composition, temperature, and reaction time. These parameter changes enable precise control over the metal-semiconductor alloy layer thickness and composition, ensuring uniform coating across all silicon particles while achieving the desired electrical conductivity.
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 provides improved electrical conductivity, reduced capacity degradation, longer cycle life, higher specific energy density, and more uniform charge/discharge characteristics compared to traditional methods, resulting in enhanced performance for nonaqueous electrolyte secondary batteries.
Implementation Method 1
contacting a portion of the anode material with a metal ion solution comprising ions of a metal and a dissolution component for dissolving a part of the semiconductor in the anode material
Implementation Method 2
reducing the ions of the metal to the metal by electrons provided by the dissolution of the semiconductor
Implementation Method 3
A uniform metal-semiconductor alloy layer is formed on anode materials through a displacement plating process
Implementation Method 4
A uniform metal-semiconductor alloy layer is formed on anode materials through a displacement plating process followed by annealing
Data Source
AI summary
The present invention relates to methods for producing anode materials for use in nonaqueous electrolyte secondary batteries. In the present invention, a metal-semiconductor alloy layer is formed on an anode material by contacting a portion of the anode material with a solution containing metals ions and a dissolution component. When the anode material is contacted with the solution, the dissolution component dissolves a part of the semiconductor material in the anode material and deposit the metal on the anode material. After deposition, the anode material and metal are annealed to form a uniform metal-semiconductor alloy layer. The anode material of the present invention can be in a monolithic form or a particle form. When the anode material is in a particle form, the particulate anode material can be further shaped and sintered to agglomerate the particulate anode material.