Silicon Anode Metal Layer for Low-Pressure Solid Electrolyte Contact
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Sulfide-based solid-state batteries with silicon anodes face issues of low ion and electron conductivity, short life characteristics due to volume changes during lithiation/delithiation, and limitations in commercialization due to high-cost processes and side reactions with solid electrolytes, especially under low pressure.
Innovation Solution
A silicon anode with a lithium-alloying metal layer, including metals like silver, tin, or aluminum, is formed to enhance interfacial contact with a sulfide-based solid electrolyte, allowing for improved delithiation capacity and coulombic efficiency even under low pressure, by forming alloys with lithium during lithiation/delithiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a silicon anode is used in sulfide-based solid-state batteries, then high energy density is achieved, but ion conductivity and electron conductivity are low and life characteristics are short due to large volume changes during lithiation/delithiation
Solution Approach 1:
The patent applies local quality by creating a specific layered structure where a lithium-alloying metal layer is positioned between the silicon anode and sulfide-based solid electrolyte. This localized modification at the interface region addresses the conductivity and stability issues without changing the bulk silicon anode properties, thereby maintaining high energy density while improving reliability.
Solution Approach 2:
The patent employs composite materials by combining silicon with a lithium-alloying metal layer to form a composite anode structure. This composite approach leverages the high capacity of silicon while the metal layer provides improved ion/electron conductivity and structural stability during volume changes, resolving the contradiction between energy density and reliability.
2Productivity
If a solid electrolyte is incorporated in a liquid state to provide ion conduction channel, then high discharge capacity is ensured, but interfacial resistance increases due to side reactions with silicon anode
Solution Approach 1:
The patent introduces a lithium-alloying metal layer as an intermediary between the silicon anode and sulfide-based solid electrolyte. This intermediate layer facilitates ion conduction (maintaining high discharge capacity) while preventing direct contact between silicon and electrolyte (reducing side reactions and interfacial resistance).
Solution Approach 2:
The patent applies parameter changes by modifying the interfacial properties through the metal layer, which alters the chemical and physical parameters at the interface. This changes the interaction between silicon and electrolyte, reducing harmful side reactions while maintaining ion conduction channels for high discharge capacity.
3Reliability
If chemical vapor deposition is used to manufacture silicon anode in column form, then volume change is induced in linear direction improving life characteristics, but cost and process difficulty increase
Solution Approach 1:
The patent extracts the essential function of volume change management from the complex chemical vapor deposition process by using a simpler metal layer deposition approach. The lithium-alloying metal layer accommodates volume changes during lithiation/delithiation without requiring expensive and complex CVD columnar structure manufacturing.
Solution Approach 2:
The patent employs a cost-effective metal layer that can be deposited using simpler, more commercially viable processes compared to chemical vapor deposition. This thinner, simpler structure achieves the volume change accommodation function at lower cost and process difficulty while maintaining improved life characteristics.
4Reliability
If high pressure is applied to form electrochemically stable interface between silicon anode and solid electrolyte, then stable interface is formed improving life characteristics, but delithiation capacity decreases under low pressure
Solution Approach 1:
The patent applies preliminary action by pre-forming the lithium-alloying metal layer during anode fabrication, which creates a stable interface structure before battery operation. This preliminary structural preparation ensures interface stability without requiring high pressure during operation, thereby maintaining delithiation capacity under normal operating conditions.
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 silicon anode with a lithium-alloying metal layer maintains uniform interfacial contact and improves battery life characteristics and capacity retention, achieving high energy density and electrochemical stability under low pressure, reducing side reactions and interfacial resistance.
Implementation Method 1
a lithium-alloying metal layer formed on the anode active material layer, wherein the lithium-alloying metal layer includes at least one selected from the group consisting of silver (Ag), tin (Sn), aluminum (Al), bismuth (Bi), gold (Au), zinc (Zn), magnesium (Mg), antimony (Sb), lead (Pb), germanium (Ge), gallium (Ga), indium (In) and silicon (Si)
Data Source
AI summary
The present disclosure relates to a silicon anode, a method for manufacturing the same, and a battery including the same. Particularly, the silicon anode improves the interfacial contact between the silicon anode and a sulfide-based solid electrolyte layer, and thus the interfacial contact can be maintained uniformly during lithiation even under low pressure, and high delithiation capacity and coulombic efficiency can be realized.In addition, the battery allows the lithium-alloying metal layer stacked on the anode active material layer to be applied to the silicon anode, and thus the lithium-alloying metal layer stacked on the silicon anode forms alloy with lithium in real time through the conduction of lithium ions from the solid electrolyte during lithiation/delithiation, and the silicon anode becomes soft and adhesive and shows improved interfacial contact between the lithium-alloying metal layer and the solid electrolyte layer, resulting in improvement of the life characteristics and capacity retention of the battery.