Lithium-Silicon Alloy-Carbon Composite for Dendrite-Controlled Anodes
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Solution Overview
Problem
The practical application of lithium metal anodes in batteries is hindered by low Coulombic efficiency and lithium dendrite formation, leading to degraded battery performance and safety issues, and pre-lithiation methods face challenges in commercial deployment due to increased cost and manufacturing complexity.
Innovation Solution
A novel lithium-silicon alloy-carbon composite is produced by impregnating lithium into a porous carbon scaffold, creating nucleation sites for lithium and reducing dendrite formation, which can be integrated into existing battery manufacturing processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If lithium metal anodes are used to achieve high specific capacity and low redox potential, then energy density is improved, but lithium dendrite formation occurs leading to low Coulombic efficiency and safety issues
Solution Approach 1:
The patent employs a porous carbon scaffold with controlled pore sizes (micropores <2 nm, mesopores 2-50 nm, and/or macropores >50 nm) to host lithium-silicon alloy domains. This porous structure prevents lithium dendrite formation by providing numerous nucleation sites and constraining lithium growth within the pore spaces, thereby maintaining high Coulombic efficiency while preserving the high energy density benefits of lithium metal anodes
Solution Approach 2:
The patent creates a composite material system consisting of carbon scaffold, silicon domains, and lithium-silicon alloy domains. This composite structure combines the advantages of each component: carbon provides structural stability and conductivity, silicon enables high lithium capacity through alloying, and the composite architecture prevents dendrite formation while maintaining high energy density and Coulombic efficiency
2Use of energy by moving object
If pre-lithiation methods are implemented to increase reversible capacity, then energy density is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent incorporates lithium into the silicon-containing porous carbon scaffold during the electrode manufacturing process itself, rather than requiring separate post-manufacturing pre-lithiation steps. This preliminary incorporation of lithium through impregnation methods (melt intrusion, electrochemical deposition, or chemical reduction) achieves the desired reversible capacity enhancement while maintaining compatibility with existing manufacturing workflows
Solution Approach 2:
The lithium-silicon alloy-carbon composite is designed to self-regulate lithium deposition during battery cycling. The porous carbon scaffold with its distributed pore structure automatically provides numerous nucleation sites that guide lithium deposition, eliminating the need for external pre-lithiation equipment or processes while maintaining high reversible capacity
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 composite provides improved first cycle efficiency, higher energy density, and enhanced cycle stability, facilitating commercial adoption and reducing the need for additional manufacturing equipment.
Implementation Method 1
the introduction of lithium can be achieved by various approaches including, but not limited to, melt intrusion, electrochemical deposition, electrode reduction, chemical reduction, lithium evaporation
Implementation Method 2
the introduction of lithium can be achieved by various approaches including, but not limited to, melt intrusion, electrochemical deposition, electrode reduction, chemical reduction, lithium evaporation
Implementation Method 3
the introduction of lithium can be achieved by various approaches including, but not limited to, melt intrusion, electrochemical deposition, electrode reduction, chemical reduction, lithium evaporation
Implementation Method 4
alloying of a metal, in particular lithium, into particles comprising silicon and a porous carbon scaffold
Data Source
AI summary
This disclosure related to particulate lithium-silicon alloy-carbon composite materials and manufacturing processes thereof, as well as corresponding devices and their corresponding manufacturing processes thereof.