Porous Current Collector Structure for Dendrite-Safe Solid-State Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
All-solid-state batteries face issues with volume change and lithium dendrite growth due to lithium plating and stripping, which can lead to safety concerns and reduced capacity.
Innovation Solution
Incorporating a porous negative electrode current collector with a stopper and pressing members to manage lithium plating and stripping within the pores, while using stoppers to prevent deformation and increase contact surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a metal current collector is used to ensure electrical conductivity and structural strength, then electrical performance and mechanical strength are improved, but interfacial resistance increases and contact with solid electrolyte deteriorates
Solution Approach 1:
The current collector uses a composite structure combining metal foil (aluminum or copper) with a conductive polymer coating. The metal provides structural strength and electrical conductivity, while the conductive polymer layer (with conductivity ≥10⁻⁵ S/cm) improves interfacial contact with the solid electrolyte and reduces interfacial resistance. This composite approach resolves the contradiction between mechanical strength and interfacial reliability.
Solution Approach 2:
The conductive polymer layer is designed with a porous structure having specific surface area of 0.03 to 3.0 mL/g. This porous structure increases the contact area between the current collector and solid electrolyte, facilitates ion transport, and reduces interfacial resistance while maintaining the structural integrity provided by the metal substrate.
2Quantity of substance
If battery capacity is increased to improve energy density, then energy storage capability is improved, but thermal runaway risk and safety hazards increase
Solution Approach 1:
The conductive polymer layer acts as an intermediary between the metal current collector and the solid electrolyte. This intermediate layer prevents direct contact that could lead to short circuits, facilitates controlled ion transport, and provides thermal buffering, thereby reducing thermal runaway risk while maintaining high battery capacity through optimized electrode design.
Solution Approach 2:
The invention changes the physical and chemical parameters of the current collector interface by introducing a conductive polymer coating with specific conductivity (≥10⁻⁵ S/cm) and porous structure (specific surface area 0.03 to 3.0 mL/g). These parameter changes improve interfacial contact, control ion flow, and enhance thermal stability, allowing higher battery capacity with reduced safety risks.
3Reliability
If solid electrolyte layer thickness is increased to improve safety and enable high voltage, then safety and voltage capability are improved, but internal resistance increases and ion transport efficiency deteriorates
Solution Approach 1:
The conductive polymer layer incorporates a porous structure with specific surface area of 0.03 to 3.0 mL/g that facilitates ion transport. This porous network provides multiple ion conduction pathways, reducing the effective transport distance and maintaining high ion transport efficiency even when the solid electrolyte layer is thickened for safety and high voltage operation.
Solution Approach 2:
The conductive polymer coating provides locally optimized properties at the current collector interface, with high conductivity (≥10⁻⁵ S/cm) and controlled porosity. This local quality enhancement at the critical interface compensates for the increased ion transport path length through the thicker solid electrolyte layer, maintaining overall ion transport efficiency while enabling safer, higher voltage battery design.
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
Prevents volume change and dendrite growth, maintaining battery safety and performance by allowing lithium to plate and strip within the porous structure, enhancing contact surfaces and reducing resistance.
Implementation Method 1
a conductive polymer porous layer that improves contact between the electrode and the solid electrolyte and facilitates ion transport
Implementation Method 2
the positive electrode current collector or the negative electrode current collector is a porous current collector having a specific surface area of 0.03 to 3.0 mL/g
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to an all-solid-state battery including a positive electrode including a positive electrode current collector coated with a positive electrode mixture layer, a negative electrode including a negative electrode current collector having a porous structure, a solid electrolyte layer located between the positive electrode and the negative electrode, a stopper disposed at an outer periphery of the negative electrode, a battery case accommodating an electrode assembly including the positive electrode, the negative electrode, and the solid electrolyte layer, and the stopper, and a pressing member disposed at each of opposite surfaces of the battery case which are parallel to planes of the positive electrode and the negative electrode respectively, the pressing member pressing in a direction toward the inside of the battery case, wherein the height of the stopper is equal to or less than the thickness of the negative electrode before pressing. Formation of lithium dendrites is inhibited, whereby safety of the all-solid-state battery is improved.