Lithium Paste Negative Electrode for Uniform Deposition and Dendrite Control
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Solution Overview
Problem
Conventional lithium metal batteries face limitations in energy and power density due to non-uniform lithium deposition, dendrite formation, limited electron/ion reaction area, and electrolyte distribution issues, which hinder their widespread application in high-energy and high-power applications.
Innovation Solution
A lithium metal negative electrode composed of a current collector coated with a lithium paste layer formed by mixing lithium powder, a thickener, and electrolyte, where lithium powder particles are uniformly dispersed, enhancing areal capacity and electron/ion reaction area, and allowing adaptive movement to reduce dendrite growth and improve cycle stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional lithium metal foil negative electrodes are used, then the battery structure is simple, but the electron/ion reaction area is limited and energy density is low
Solution Approach 1:
The lithium metal foil is segmented into numerous lithium powder particles with diameters of 1-30 μm, which are then dispersed in the electrolyte to form a paste layer. This segmentation dramatically increases the total surface area available for electron/ion reactions while maintaining a relatively simple overall electrode structure consisting of a current collector and paste layer.
2Quantity of substance
If conventional lithium metal negative electrodes are used, then the electrode structure is simple, but the areal capacity is limited
Solution Approach 1:
The invention changes the physical state of lithium from solid foil to a paste consisting of fine particles suspended in electrolyte. By controlling particle size (1-30 μm) and concentration (10-60 parts lithium powder per 30-80 parts electrolyte), the areal capacity is significantly increased while the electrode maintains a simple two-layer structure.
3Power
If high current charging is applied to conventional lithium metal batteries, then the power density increases, but lithium deposits non-uniformly and dendrites form
Solution Approach 1:
The paste layer provides numerous localized deposition sites distributed uniformly across the electrode surface. Each lithium powder particle acts as a local reaction site, ensuring uniform current distribution and preventing localized dendrite formation even during high current charging, thereby maintaining both power density and safety.
4Duration of action of stationary object
If conventional lithium metal negative electrodes are used, then the electrode is easy to manufacture, but the cycle stability is poor due to expansion and contraction
Solution Approach 1:
The lithium powder particles in the paste layer are free to move and adapt their positions during charging and discharging cycles. This dynamic arrangement allows the electrode to accommodate volume changes without structural degradation, significantly improving cycle stability while maintaining a simple manufacturing process of coating and drying.
5Stability of the object's composition
If conventional lithium metal negative electrodes are used, then the electrode structure is simple, but the electrolyte distribution is uneven during storage
Solution Approach 1:
The electrolyte serves dual functions: as the medium for ionic conduction during battery operation and as a dispersant that maintains uniform distribution of lithium powder particles during storage. The thickener adds viscosity to prevent particle sedimentation, ensuring the electrolyte remains uniformly distributed without complicating the basic electrode structure.
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 lithium paste layer improves high energy and power density, cycle stability, and electrolyte distribution, facilitating the production of lithium metal batteries with enhanced safety and efficiency.
Implementation Method 1
lithium powder particles are uniformly dispersed in the electrolyte
Implementation Method 2
the lithium powder particles can be move adaptively in the electrolyte during the charging and discharging of the lithium metal battery
Implementation Method 3
the lithium powder particles themselves and the thickener in the lithium paste have a certain liquid retention capacity for the electrolyte
Data Source
AI summary
Disclosed are a lithium metal negative electrode, a preparation method therefor, and a lithium battery using the negative electrode. The preparation method for the lithium metal negative electrode is as follows: selecting a lithium salt and an organic solvent and mixing same to formulate an electrolyte, and uniformly mixing the electrolyte and a thickener at a ratio to obtain a viscous liquid A, then adding a lithium powder with a volume equivalent diameter of 1-30 µm to the viscous liquid A at a ratio, stirring and mixing same until uniform to obtain a pasty lithium paste, and uniformly applying the lithium paste on a current collector to obtain the lithium metal negative electrode.