Solid-State Battery Layer Structure for High-Capacity Silicon Anodes
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Solution Overview
Problem
Existing solid-state batteries face challenges in improving charge capacity and addressing material-dependent volume expansion, which are not adequately addressed in prior art.
Innovation Solution
A solid-state battery layer structure comprising a silicon anode layer with gallium nitride additions and nanowire structures, enclosed by a lithium phosphate solid electrolyte, and a lithium cobalt oxide cathode, utilizing microelectronic fabrication methods for integration and miniaturization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional graphite anodes are used, then the battery structure is simple and easy to manufacture, but the charge capacity is limited
Solution Approach 1:
The patent employs composite anode materials consisting of silicon particles embedded in a carbon matrix, with additional lithium phosphate coating. This composite structure combines the high charge capacity of silicon with the structural stability and conductivity of carbon, while the lithium phosphate layer prevents degradation. This directly resolves the contradiction by achieving superior charge capacity without excessive structural complexity.
Solution Approach 2:
The invention applies different materials to different regions of the anode: silicon particles are distributed within the carbon matrix, and lithium phosphate is selectively deposited on the silicon surface. This local differentiation optimizes each region's function - silicon for capacity, carbon for structure, and lithium phosphate for protection - thereby achieving high charge capacity while maintaining manufacturability.
2Quantity of substance
If silicon anodes are used to increase charge capacity, then charge capacity improves, but volume expansion occurs during charging
Solution Approach 1:
The patent utilizes a carbon matrix as a flexible container that can accommodate silicon's volume expansion during charging. The carbon shell acts as a buffer that absorbs mechanical stress, preventing structural collapse while allowing silicon to expand. This resolves the contradiction by maintaining charge capacity benefits while managing volume changes through the flexible carbon framework.
Solution Approach 2:
The invention embeds silicon particles within the carbon matrix structure, creating a nested configuration where silicon is contained within carbon. This nested structure allows silicon to expand and contract within the carbon framework without causing overall anode deformation, thereby achieving high charge capacity while controlling volume expansion.
3Reliability
If solid electrolytes are used to reduce fire risk, then safety improves, but novel battery designs are required
Solution Approach 1:
The patent employs lithium phosphate, which serves multiple functions: it acts as a solid electrolyte providing fire safety, simultaneously serves as a protective coating on silicon anode particles, and facilitates lithium ion transport. This multi-functionality reduces the need for additional separate components, thereby achieving improved safety while limiting design complexity.
Solution Approach 2:
The invention merges the electrolyte function with the protective coating function by using lithium phosphate for both purposes. Instead of requiring separate electrolyte and protective layer components, the lithium phosphate serves dual roles, simplifying the overall battery design while maintaining fire safety benefits of solid electrolytes.
4Quantity of substance
If sophisticated fabrication techniques are used to create silicon anodes, then charge capacity increases, but manufacturing complexity and cost increase
Solution Approach 1:
The patent extracts the essential function of complex silicon anode fabrication by focusing on the key element - silicon particles embedded in carbon - and eliminating unnecessary sophisticated processing steps. The method uses straightforward carbonization of precursors and simple lithium phosphate deposition, achieving high charge capacity through material selection rather than complex fabrication, thereby improving ease of manufacture.
Solution Approach 2:
The invention optimizes manufacturing by controlling key parameters such as carbonization temperature and lithium phosphate deposition conditions, rather than requiring sophisticated fabrication techniques. By adjusting these parameters within specific ranges, high charge capacity is achieved through material composition control rather than complex processing, thereby improving ease of manufacture while maintaining performance.
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 structure enhances charge capacity by up to 2.5 times that of conventional graphite anodes and mitigates volume expansion, enabling rapid charging and integration with silicon-based microelectronics.
Implementation Method 1
silicon atoms, often alloyed to form compound anode materials, are better than carbon atoms, in conventional graphite anodes, at binding to and thus holding a larger number of lithium atoms
Implementation Method 2
a solid electrolyte layer arranged on the anode layer laterally
Implementation Method 3
The diffusion barrier for lithium-ion diffusion may also be lower with a gallium nitride anode compared to the same barrier for a graphite anode
Data Source
AI summary
This disclosure is directed toward a method for producing a solid-state battery layer structure. The method may include providing an anode layer comprising silicon, forming a plurality of nanowire structures including silicon and/or gallium nitride on the anode layer and depositing a solid electrolyte layer on the anode layer. In some examples, the method may also include depositing a cathode layer on the solid electrolyte layer, depositing a cathode current collector metal layer on the cathode layer, etching holes through the anode layer, filling the holes with an electrically conducting material; and depositing an anode current collector metal layer on a bottom surface of the anode layer.