3D Lithium Metal Anode Framework for Bottom-Up Deposition
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Solution Overview
Problem
Lithium metal batteries face issues with lithium dendrite formation and solid electrolyte interface (SEI) film peeling due to lithium metal deposition during charging and discharging, leading to reduced Coulombic efficiency and cycle performance.
Innovation Solution
A secondary battery design featuring a negative electrode plate with a three-dimensional framework composed of a first and second framework layer, including one-dimensional conductive fibers, zero-dimensional, and two-dimensional materials, which creates a lithiophilic gradient to facilitate controlled lithium metal deposition and reduce dendrite formation, enhancing Coulombic efficiency and cycle performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If lithium metal is used in the negative electrode to achieve high energy density, then the gravimetric specific energy is improved, but lithium dendrites and dead lithium form during charging and discharging
Solution Approach 1:
The patent applies local quality by creating a non-uniform lithiophilic gradient within the three-dimensional framework structure. Different regions of the framework have varying lithiophilic properties, with stronger lithiophilia at certain locations to guide uniform lithium deposition. This gradient distribution prevents localized dendrite formation while maintaining high lithium capacity, thus preserving high gravimetric specific energy while improving Coulombic efficiency.
Solution Approach 2:
The three-dimensional framework acts as an intermediary between the lithium metal and the electrolyte. This framework mediates the lithium deposition process by providing a controlled interface that guides lithium ion insertion. The framework's porous structure and lithiophilic properties facilitate uniform lithium distribution, preventing direct uncontrolled lithium plating that causes dendrites, while still enabling high lithium storage capacity.
2Use of energy by moving object
If lithium metal is used in the negative electrode to achieve high energy density, then the gravimetric specific energy is improved, but the SEI film peels and fragments during charging and discharging
Solution Approach 1:
The three-dimensional framework provides a flexible, porous matrix that accommodates lithium metal volume changes during charging and discharging cycles. This framework structure acts as a stable support that prevents SEI film fragmentation by distributing mechanical stress uniformly. The framework's three-dimensional architecture allows for volume expansion and contraction without compromising structural integrity, thus maintaining SEI film stability while enabling high lithium capacity.
Solution Approach 2:
The patent employs composite materials by combining the three-dimensional framework with lithiophilic materials to create a composite negative electrode structure. This composite architecture integrates the high capacity of lithium metal with the structural stability of the framework. The composite structure provides both the lithiophilic properties needed for uniform lithium deposition and the mechanical stability required to prevent SEI film peeling, thus achieving high gravimetric specific energy with improved cycle stability.
3Reliability
If a three-dimensional framework with lithiophilic gradient is constructed to reduce lithium dendrites, then the Coulombic efficiency is improved, but the device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the negative electrode into a three-dimensional framework structure with distinct layers and regions. The framework is segmented into multiple components including conductive fiber networks and active material particles distributed throughout the porous structure. This segmentation creates the lithiophilic gradient needed for uniform lithium deposition while maintaining a manufacturable structure through conventional electrode fabrication techniques, thus improving Coulombic efficiency without excessive complexity.
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 controlled lithium metal deposition and reduced dendrite formation improve the battery's Coulombic efficiency and cycle performance by suppressing volume expansion and maintaining high electronic conductivity, leading to enhanced safety and performance.
Implementation Method 1
a lithiophilic gradient is favorably constructed in the three-dimensional framework, so as to enable lithium metal to enter the interior of the three-dimensional framework and deposit from bottom upward
Implementation Method 2
The zero-dimensional material is a lithiophilic material... the zero-dimensional material exhibits a tip effect and is a lithiophilic material, and is dispersed in the two-dimensional material, thereby reducing the nucleation overpotential of the lithium metal and inducing the lithium metal to deposit
Implementation Method 3
the lithium metal deposited in the pores of the three-dimensional framework can suppress the volume expansion of the lithium metal, thereby improving the expansion resistance of the secondary battery
Implementation Method 4
The first framework layer includes one-dimensional conductive fibers... improving the electronic conductivity in the three-dimensional framework
Data Source
AI summary
A secondary battery includes a negative electrode plate and a separator. The negative electrode plate includes a three-dimensional framework. The three-dimensional framework includes a first framework layer and a second framework layer. The first framework layer includes one-dimensional conductive fibers. The second framework layer includes a zero-dimensional material, a one-dimensional material, and a two-dimensional material. The zero-dimensional material is a lithiophilic material. By adjusting and controlling the thicknesses of the three-dimensional framework, the first framework layer, and the second framework layer, the mass percent of the zero-dimensional material, and the mass ratio between the one-dimensional material and the two-dimensional material to fall within the ranges specified herein, a lithiophilic gradient is favorably constructed in the three-dimensional framework, so as to enable lithium metal to enter the interior of the three-dimensional framework and deposit from bottom upward, thereby improving the Coulombic efficiency and cycle performance of the secondary battery.