Microporous Carbon-Coated Negative Electrode for Uniform Metal Deposition
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Solution Overview
Problem
Anode-free metal batteries suffer from low Coulombic efficiency and short cycle life due to uneven metal deposition and dendrite growth on the negative electrode, which affects energy density and cycling performance.
Innovation Solution
A negative electrode with a flexible carbon material coating containing micropores less than 0.8 nm and a specific pore volume ratio, along with oxygen-containing functional groups, is used to regulate metal deposition, forming a uniform metal layer and reducing dendrite formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If anode-free metal batteries are used to achieve high energy density, then energy density is improved, but Coulombic efficiency deteriorates and cycle life becomes short
Solution Approach 1:
A flexible carbon material coating layer is introduced as an intermediary between the metal anode and electrolyte. This coating layer with controlled micropore structure (Vmic:Vtotal ≥ 65:100) serves as a mediator that regulates metal ion deposition, preventing direct harmful interactions while maintaining high energy density benefits of anode-free design
Solution Approach 2:
The flexible carbon material coating is designed with a specific porous structure where micropores (diameter ≤ 0.8 nm) constitute at least 65% of total pore volume. This porous structure allows controlled ion transport and provides nucleation sites for uniform metal deposition, resolving the contradiction between high energy density and reliable cycling performance
2Use of energy by moving object
If metal deposition is allowed to proceed without control, then energy density is maximized, but uneven deposition and dendrite growth occur
Solution Approach 1:
The flexible carbon material coating provides locally optimized deposition sites through its micropore structure. The micropores (diameter ≤ 0.8 nm) act as localized nucleation centers that guide uniform metal ion distribution, ensuring precise control over metal deposition morphology while maintaining high energy density
Solution Approach 2:
The flexible carbon material coating is pre-applied to the metal anode surface before battery operation. This preliminary action creates a controlled interface that pre-determines uniform metal deposition patterns, preventing dendrite formation from the outset while preserving the high energy density benefits
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 energy density and cycling performance by ensuring uniform metal deposition and minimizing dendrite growth, leading to improved battery performance.
Implementation Method 1
These micropores are typically located at the positions of edge carbon atoms in the flexible carbon material, which can reduce an overpotential of a metal (such as sodium), and serve as initial nucleation sites during deposition of a metal, thereby lowering a nucleation barrier of the metal
Implementation Method 2
The flexible carbon material may exhibit excellent conductivity and stability, enabling the construction of an effective conductive network in the negative electrode, thereby reducing an internal resistance of the battery
Implementation Method 3
The oxygen-containing functional group can modify the flexible carbon material, expanding an interlayer spacing and increasing a metal storage space
Data Source
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AI summary
This application provides a negative electrode and a preparation method therefor, a battery cell containing the same, a battery, and an electric apparatus, where the negative electrode includes a negative electrode current collector and a coating disposed on at least one surface of the negative electrode current collector, the coating includes a flexible carbon material, the flexible carbon material includes micropores with a pore diameter less than or equal to 0.8 nm, a pore volume of the micropores with a pore diameter less than or equal to 0.8 nm is denoted as Vmic, a pore volume of the flexible carbon material is denoted as Vtotal, both in units of cm3/g, and Vmic:Vtotal≥65:100.