Graded Lithium-Ion Conducting Layer for Anode Protection
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Solution Overview
Problem
Lithium-ion batteries face limitations in energy density, service life, and safety due to the reactivity of lithium anodes, which leads to dendrite formation and increased internal resistance, and existing protective layers compromise ionic conductivity.
Innovation Solution
A lithium-based energy accumulator electrode with a substrate and active anode layer featuring a lithium-ion-conducting layer with a gradually changing material composition, comprising ceramic or polymer materials that form a protective layer to stabilize the anode, preventing dendrite growth and maintaining high ionic conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a protective layer is applied to the lithium anode, then the service life and safety are improved, but the ionic conductivity is greatly reduced due to boundary layer resistance
Solution Approach 1:
The patent applies a protective layer with spatially varying lithium content - the layer has higher lithium concentration near the lithium anode interface and lower lithium concentration toward the electrolyte interface. This gradient structure provides high ionic conductivity near the anode while maintaining protective functions toward the electrolyte, thus resolving the contradiction between protection and ionic conductivity.
Solution Approach 2:
The patent changes the composition parameter of the protective layer by controlling the lithium content gradient through deposition conditions. By varying the lithium fraction from 0.1 to 0.9 in different regions of the layer, the patent optimizes both protective performance and ionic conductivity, transforming a uniform protective layer into a functionally graded material.
2Object-affected harmful factors
If a protective layer is applied to the lithium anode, then dendrite formation is prevented, but the internal resistance increases due to boundary layer resistance
Solution Approach 1:
The protective layer is designed with non-uniform lithium distribution, having higher lithium content near the anode interface to maintain low resistance and lower lithium content toward the electrolyte to provide protection. This local variation in composition allows the layer to simultaneously prevent dendrites while minimizing resistance increase.
Solution Approach 2:
The patent creates a composite protective layer structure combining regions with different lithium concentrations (0.1 to 0.9), effectively creating a functionally graded composite material that integrates the benefits of both high-lithium regions (low resistance) and low-lithium regions (protection).
3Object-affected harmful factors
If a protective layer is applied to the lithium anode, then the reactivity with electrolyte is reduced, but the adhesion worsens due to sharply formed dividing line
Solution Approach 1:
The patent eliminates sharp interfaces by creating a protective layer with gradual lithium concentration gradient. The higher lithium content regions near the anode provide strong adhesion, while the lower lithium content regions toward the electrolyte provide chemical protection, thus maintaining both adhesion and reactivity protection simultaneously.
4Quantity of substance
If lithium-containing anodes are used instead of carbon anodes, then the energy density is improved, but the safety and service life are worsened due to lithium reactivity
Solution Approach 1:
The patent introduces a protective layer as an intermediary between the lithium anode and the electrolyte. This intermediate layer prevents direct contact and harmful reactions between lithium and electrolyte, thereby enabling the use of high-energy-density lithium anodes while maintaining safety and service life.
Solution Approach 2:
The patent creates a composite anode structure combining lithium metal with a protective layer having graded lithium content (0.1 to 0.9). This composite structure preserves the high energy density of lithium while the protective layer component provides safety and stability.
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 enhances the service life and cycling efficiency of lithium-ion batteries by forming a stable protective layer that prevents dendrite formation and maintains high ionic conductivity, ensuring improved robustness and safety while maintaining high energy density.
Implementation Method 1
at least one lithium-ion-conducting layer, wherein the lithium-ion-conducting layer has a material composition which gradually changes over a layer thickness
Data Source
AI summary
An electrode for an energy accumulator comprises a substrate, an active anode layer having an active anode material, the active anode material being at least partially a lithium, a lithium alloy and/or a lithium intercalation material, at least one lithium-ion-conducting layer having a material composition which gradually changes over a layer thickness and has at least one lithium-ion-conducting component. A method for forming an electrode for an energy accumulator, and a lithium-ion battery comprising an electrode are also disclosed.