Lithium Battery Electrode Structure for Controlled Dendrite Plating
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Solution Overview
Problem
Conventional lithium batteries face challenges with lithium dendrite formation, which leads to capacity degradation and safety issues due to dendrite penetration through the separator, and existing solutions like additives in the electrolyte or using lithium titanium oxide as an active material either reduce lithium deposition efficiency or lower energy density.
Innovation Solution
A lithium battery structure with two active material layers of the same polarity arranged face-to-face, featuring a conductive substrate with through holes and an isolation layer, and an ion guiding layer with high surface area pores to control lithium dendrite growth and enhance ion exchange efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additives are added to the electrolyte to reduce lithium deposition, then lithium dendrite formation is reduced, but side effects reduce the efficiency of internal electrochemical reactions
Solution Approach 1:
The patent removes additives from the electrolyte system entirely, replacing them with a physical structural approach using a current collector with through-holes and isolation layers. This extracts the harmful side effects associated with additives while maintaining the core function of controlling lithium deposition through geometric constraints rather than chemical interference.
Solution Approach 2:
The patent introduces an intermediary structure (the current collector with through-holes and isolation layers) that mediates between the electrolyte and the electrode. This intermediary physically guides lithium ion deposition into controlled regions, acting as a mediator that prevents uncontrolled dendrite formation without requiring chemical additives that would interfere with electrochemical reactions.
2Reliability
If lithium titanium oxide is used as the anode active material to avoid lithium deposition, then lithium deposition is prevented, but the discharge voltage is reduced to about 2.4V and energy density is sacrificed
Solution Approach 1:
The patent applies local quality by creating specific regions on the current collector with different functions: through-holes that provide isolation and guide lithium deposition in certain areas, while other areas maintain normal electrode structure. This localized structural modification prevents lithium deposition without requiring a complete change to low-voltage materials like lithium titanium oxide, thereby preserving high energy density.
Solution Approach 2:
The patent changes the physical parameters of the current collector (adding through-holes and isolation layers) rather than changing the electrochemical parameters of the active material. This parameter change in the collector structure provides the deposition control function previously achieved by material substitution, allowing the use of high-voltage, high-energy-density materials to be maintained.
3Device complexity
If conventional current collectors are used without through-holes, then the structure is simple, but lithium dendrites can penetrate through the separator causing internal shorts or explosions
Solution Approach 1:
The patent segments the current collector by creating through-holes that divide the collector into isolated regions. This segmentation physically separates the electrode surface into multiple controlled zones, preventing continuous lithium dendrite growth paths that could penetrate the separator. The segmentation approach maintains structural integrity while introducing safety features.
Solution Approach 2:
The isolation layers formed in the through-holes act as intermediaries between the electrolyte and the electrode surface. These intermediary structures provide a controlled interface that guides lithium ion deposition and prevents uncontrolled dendrite formation, mediating the interaction between the electrolyte and electrode without requiring complex external safety systems.
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
This configuration limits lithium dendrite growth between the active material layers, reducing the risk of internal shorts and explosions, increases cycle life by utilizing dendrites as a lithium source, and maintains high energy density.
Implementation Method 1
an ion guiding layer with high surface area pores to control lithium dendrite growth and enhance ion exchange efficiency
Implementation Method 2
an isolation layer, and an ion guiding layer... The isolation layer is disposed on the first surface of the conductive substrate and covers the sidewalls of the through holes
Implementation Method 3
the lithium dendrite is limited to be plated between the two active material layers... increases cycle life by utilizing dendrites as a lithium source
Data Source
Figure 1
Figure 2A~2B
Figure 2C~4
AI summary
The invention discloses a lithium battery structure and the electrode layer thereof. The lithium battery structure includes two battery units with the two negative active material layers being disposed in face-to-face arrangement. The negative current collector includes a conductive substrate with a plurality of through holes and an isolation layer. The isolation layer is covered on one surface of the conductive substrate and extended along the through holes to another surface to cover the edge of the openings of the through holes. It can be effectively avoided the lithium dendrites depositing near the openings of the through holes on the conductive substrate. Also, the face-to-face arrangement of the negative active material layers is effectively control the locations of the plated lithium dendrites. Therefore, the safety of the battery and the cycle life of the battery is greatly improved.