Carbon Matrix Dendrite-Intercepting Layer for Alkali Metal Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rechargeable lithium metal and sodium metal batteries face significant challenges due to dendrite formation and penetration, which leads to internal shorting and safety issues, limiting their energy density and cycle life, especially in lithium-sulfur and sodium-sulfur batteries operating at room temperature.
Innovation Solution
A dendrite penetration-resistant layer composed of an amorphous carbon or polymeric carbon matrix with carbon or graphite reinforcement phases, chemically bonded with lithium or sodium-containing species, is implemented between the anode and separator to prevent dendrite penetration, allowing for high energy density and long cycle life while ensuring safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a rigid solid protective layer (ceramic material) is used between the anode and separator to stop dendrite penetration, then dendrite penetration resistance is improved, but ion conductivity deteriorates and manufacturing complexity increases
Solution Approach 1:
The patent changes the physical and chemical parameters of the protective layer by using amorphous carbon matrix with specific lithium-containing species (Li2CO3, Li2O, LiOH, LiX) formed through electrochemical decomposition. This transforms the layer from a rigid ceramic structure to a flexible carbon-based structure with controlled ionic conductivity, resolving the contradiction between dendrite resistance and manufacturing ease
Solution Approach 2:
The patent creates a composite structure consisting of amorphous carbon matrix combined with lithium-containing species formed in situ. This composite material provides both the mechanical strength needed to intercept dendrites and the ionic conductivity required for battery operation, while being compatible with existing manufacturing processes
2Use of energy by moving object
If lithium metal anode is used to achieve high energy density, then specific energy is improved, but dendrite formation increases causing safety issues
Solution Approach 1:
The patent introduces a carbon-based intermediary layer between the lithium metal anode and the separator. This intermediary layer acts as a physical barrier that intercepts dendrites while allowing ionic transport, enabling the use of high-energy lithium metal anodes without the safety hazards of dendrite penetration
Solution Approach 2:
The patent applies preliminary electrochemical decomposition treatment to form the protective carbon layer with lithium-containing species before the battery enters normal operation. This preliminary action creates a stable interface that prevents subsequent dendrite formation and ensures safe operation throughout the battery cycle
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 effectively stops dendrite penetration, achieving a specific energy of over 500 Wh/kg in lithium-sulfur or sodium-sulfur cells, enhancing safety and cycle stability, and is cost-effective and easy to implement.
Implementation Method 1
the carbon matrix or carbon matrix composite is chemically active and capable of bonding with lithium- or or sodium-containing species formed through electrochemical decomposition
Data Source
AI summary
A dendrite penetration-resistant layer for a rechargeable alkali metal battery, comprising an amorphous carbon or polymeric carbon matrix, an optional carbon or graphite reinforcement phase dispersed in this matrix, and a lithium- or sodium-containing species that are chemically bonded to the matrix and/or the optional carbon or graphite reinforcement phase to form an integral layer that prevents dendrite penetration through this integral layer in the alkali metal battery, wherein the lithium- or sodium-containing species is selected from Li2CO3, Li2O, Li2C2O4, LiOH, LiX, ROCO2Li, HCOLi, ROLi, (ROCO2Li)2, (CH2OCO2Li)2, Li2S, LixSOy, Na2CO3, Na2O, Na2C2O4, NaOH, NaX, ROCO2Na, HCONa, RONa, (ROCO2Na)2, (CH2OCO2Na)2, Na2S, NaxSOy, or a combination thereof, wherein X═F, Cl, I, or Br, R=a hydrocarbon group, x=0−1, y=1−4; and wherein the lithium- or sodium-containing species is derived from an electrochemical decomposition reaction.