Solid-State Battery Interfacial Layer for Dendrite Suppression
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Solution Overview
Problem
Larger lithium (Li) metal solid state electrolyte (SSE) batteries face issues such as interface reactions leading to resistive layers, damage to softer anode or cathode materials, and lithium deposition causing dendrite growth and shorts, which are exacerbated in crystalline SSEs, hindering the development of high-density electric drive vehicle (EDV) batteries.
Innovation Solution
Incorporation of an interfacial layer, such as a porous polymer or Li Halide layer, between the anode and SSE, and optionally between the cathode and SSE, acting as a shock absorber and improving ionic conductance, preventing lithium deposition and dendrite growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a solid state electrolyte (SSE) is used directly in contact with the anode, then the battery structure is simple, but interface reactions form resistive layers and cause lithium deposition leading to dendrite growth
Solution Approach 1:
A soft protective layer is introduced as an intermediary between the SSE and the anode. This layer acts as a mediator that prevents direct contact between the hard SSE and soft anode/cathode materials, thereby preventing interface reactions, lithium deposition, and dendrite growth while maintaining structural simplicity
Solution Approach 2:
The soft protective layer is applied beforehand to cushion and protect the softer electrode materials from damage by the harder SSE. This prior cushioning prevents mechanical damage and interface defects before they can occur during battery operation
2Reliability
If a crystalline SSE is used, then the ionic conductance is high, but the hardness causes damage to softer anode or cathode materials
Solution Approach 1:
The soft protective layer serves as a intermediary that decouples the mechanical interaction between the hard crystalline SSE and soft electrodes from the ionic conduction function. The SSE maintains its high ionic conductance while the soft layer absorbs mechanical stress and prevents electrode damage
Solution Approach 2:
The soft protective layer is applied beforehand to cushion the softer electrode materials from the harder crystalline SSE, preventing mechanical damage while allowing the crystalline SSE to maintain its superior ionic conductance properties
3Object-affected harmful factors
If the anode and cathode materials are made softer to improve safety, then the mechanical safety is improved, but the materials are more susceptible to damage from the harder SSE
Solution Approach 1:
The soft protective layer acts as a intermediary that protects the soft electrode materials from damage by the harder SSE. It creates a protective interface that allows the electrodes to remain soft for safety while being shielded from mechanical damage
Solution Approach 2:
The soft protective layer provides beforehand cushioning to the softer electrode materials, preventing mechanical damage from the harder SSE while allowing the electrodes to maintain their soft, safe characteristics
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 interfacial layer enhances the safety and performance of SSE batteries by accommodating volume changes, improving ionic conductance, and preventing dendrite growth, enabling the development of stable large-format batteries.
Implementation Method 1
the interfacial layer may improve ionic conductance between the anode and the SSE and/or the SSE and the cathode
Implementation Method 2
the interfacial layer may act as a shock absorber between a SSE (e.g., a sulfide glass SSE) and an anode material that is soft compared to the SSE
Implementation Method 3
the interfacial layer may prevent or deter lithium deposition and dendrite growth at the interface between the anode and the SSE
Data Source
AI summary
The problems or issues faced by typical larger SSE batteries are solved by providing an interface or interfacial layer at least between the anode, which comprises Li or Na, and the solid state electrolyte (SSE). In some other embodiments, an interfacial layer may be provided between the anode, which comprises Li or Na, and the SSE, and an interface or interfacial layer may also be provided between the cathode and the SSE. In at least selected embodiments, aspects or objects, the interfacial layer may act as a shock absorber between a SSE (e.g., a sulfide glass SSE) and an anode material that is soft compared to the SSE (e.g., Li metal). In other embodiments, the interfacial layer may act as a shock absorber between the SSE and a cathode material that is softer than the SSE. In at least certain embodiments, the interfacial layer may improve ionic conductance between the anode and the SSE and/or the SSE and the cathode. In at least certain selected embodiments, the interfacial layer may prevent or deter lithium deposition and dendrite growth at the interface between the anode and the SSE. Interface defects at the interface between the anode and the SSE may allow lithium deposition and dendrite growth. The dendrites may continue to grow through cracks in the SSE causing a short, which is a safety issue. The inventive interfacial layer between the anode and the SSE may prevent or deter this. In at least some embodiments, the interfacial layer may be a porous polymer layer filled with liquid electrolyte and may improve ionic conductance between the anode and the SSE and/or the SSE and the cathode. In certain embodiments, the anode interface or interfacial layer may be a porous polymer layer filled with liquid electrolyte. In some embodiments, the cathode interface or interfacial layer may be a porous polymer layer filled with liquid, gel or polymer electrolyte.