Lithium Battery Electrode Structure for Dendrite-Constrained Plating
Find Innovative SolutionsGenerate Solutions
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 reduce energy density and efficiency.
Innovation Solution
A lithium battery structure with two active material layers of the same polarity arranged face-to-face, incorporating an ion guiding layer with high surface area pores to guide electrolyte and control lithium dendrite formation between the layers, reducing the likelihood of dendrite penetration and enhancing ion exchange efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional lithium battery structure with single anode electrode is used, then lithium deposition occurs on current collector surface, but lithium dendrite formation leads to capacity degradation and safety issues
Solution Approach 1:
The patent divides the single anode electrode into two separate anode electrodes (first and second anode electrodes) with the same polarity, arranged facing each other. This segmentation prevents lithium dendrites from forming on the current collector surface by providing alternative deposition sites on the active material surfaces, thereby eliminating the harmful dendrite growth that compromises safety.
Solution Approach 2:
The patent introduces a separator positioned between the two anode electrodes that allows ion transport but physically blocks lithium dendrite penetration. This intermediary structure enables the system to tolerate controlled lithium deposition while preventing the harmful effect of dendrites penetrating through to cause short circuits or thermal runaway.
2Object-generated harmful factors
If additives are added to electrolyte to reduce lithium deposition, then lithium dendrite formation is reduced, but side effects reduce efficiency of internal electrochemical reaction
Solution Approach 1:
The patent removes the need for electrolyte additives by extracting the lithium deposition problem from the electrolyte system and relocating it to the electrode structure. By providing two anode electrodes with active material surfaces, the system naturally controls lithium deposition without requiring chemical additives that would compromise electrochemical reaction efficiency.
3Object-generated harmful factors
If lithium titanium oxide is used as anode active material to avoid lithium deposition, then potential is raised above 0 volts, but discharge voltage reduces to about 2.4V and energy density is sacrificed
Solution Approach 1:
The patent applies local quality by using different active materials in different regions of the battery system. The two anode electrodes can use conventional low-potential active materials (maintaining high energy density) while the cathode uses high-potential material. The face-to-face arrangement with separator ensures lithium deposits on anode active material surfaces rather than current collector, avoiding dendrites without sacrificing energy density.
4Object-generated harmful factors
If two active material layers with same polarity are arranged face to face, then lithium dendrite growth is limited between layers, but separator penetration risk remains
Solution Approach 1:
The patent implements beforehand cushioning by positioning the separator in advance between the two anode electrodes. This pre-positioned barrier provides a safety cushion that absorbs and blocks any lithium dendrites that might form and grow between the electrodes, preventing them from penetrating through to cause short circuits or thermal runaway events.
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 effectively limits lithium dendrite growth, increases cycle life, and maintains high energy density by using the dendrites as a lithium source, reducing internal shorts and improving safety.
Implementation Method 1
incorporating an ion guiding layer with high surface area pores to guide electrolyte
Implementation Method 2
the lithium deposition is continued on the surface of the current collector, resulting in the formation of a large amount of lithium dendrite
Data Source
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.