Silicon Anode with Metal Matrix for Battery Swelling Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium ion secondary batteries using silicon as an anode active material face challenges with cycle characteristics and swelling due to pulverization of the anode active material layer during charge and discharge, leading to reduced battery performance.
Innovation Solution
Incorporating a metal material with a metal element not alloyed with the electrode reactant between silicon anode active material particles to enhance binding and prevent pulverization, with the metal material covering exposed faces and filling gaps within the anode active material layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If silicon is used as anode active material to improve battery capacity, then theoretical capacity is significantly increased, but the anode active material layer is pulverized during charge and discharge
Solution Approach 1:
The invention uses a composite structure where silicon anode active material particles are embedded in a metal matrix. The metal material (such as aluminum, copper, or nickel) forms a continuous phase that binds the silicon particles together, creating a composite anode active material layer that maintains structural integrity while utilizing the high capacity of silicon.
Solution Approach 2:
The metal material acts as an intermediary between the silicon particles and the current collector. It provides a binding mechanism that prevents pulverization during charge-discharge cycles, while also serving as a conductive matrix that maintains electrical connectivity throughout the anode active material layer.
2Ease of manufacture
If the anode active material layer is formed by vapor-phase deposition of silicon, then the anode active material can be deposited, but the binding characteristics are not sufficient
Solution Approach 1:
The invention creates a composite structure where vapor-deposited silicon particles are embedded in a metal matrix. The metal phase provides the binding characteristics that pure vapor-deposited silicon lacks, while the silicon particles maintain their high capacity properties.
Solution Approach 2:
The invention changes the material composition parameter by introducing metal elements into the anode active material layer. This compositional change transforms the binding characteristics from insufficient (pure silicon) to adequate (silicon-metal composite).
3Quantity of substance
If the anode active material layer is pulverized, then the surface area increases, but irreversible lithium oxide is excessively formed and current collectivity is lowered
Solution Approach 1:
The metal matrix serves as an intermediary that constrains the silicon particles, preventing excessive pulverization. It maintains a balanced surface area increase that is sufficient for lithium insertion/extraction while preventing the excessive surface area that would lead to excessive irreversible lithium oxide formation.
Solution Approach 2:
The metal matrix acts as a flexible binding network that accommodates the expansion and contraction of silicon particles during charge-discharge cycles. This flexible structure prevents brittle fracture and excessive pulverization, maintaining structural integrity throughout cycling.
4Strength
If the anode active material layer is pulverized, then the anode active material falls from the current collector, but the binding characteristics need to be improved
Solution Approach 1:
The invention uses a composite anode active material layer where silicon particles are embedded in a metal matrix. This composite structure inherently provides binding characteristics that prevent material fall-off, while maintaining a relatively simple overall anode structure consisting of the current collector, anode active material layer, and protective coating.
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
Improves cycle characteristics and reduces swelling, maintaining battery performance by preventing anode active material layer separation and expansion, thus enhancing the battery's capacity retention and structural integrity.
Implementation Method 1
Incorporating a metal material with a metal element not alloyed with the electrode reactant between silicon anode active material particles to enhance binding and prevent pulverization
Implementation Method 2
when charge and discharge are repeated, there is a possibility that the anode active material layer is largely expanded and shrunk to be pulverized
Data Source
AI summary
A battery capable of improving the cycle characteristics and the swollenness characteristics is provided. The battery includes a cathode, an anode, and an electrolytic solution. The node has an anode current collector and an anode active material layer provided thereon, and the anode active material layer contains a plurality of anode active material particles having silicon, and a metal material having a metal element not being alloyed with an electrode reactant in a gap between the anode active material particles.