Interpenetrating Electrodes for Solid-State Li-Ion Batteries
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Solution Overview
Problem
Solid-state lithium-ion batteries face challenges with slow Li-ion diffusion rates and reduced energy density due to the use of thin layers to compensate for slow diffusion, limiting their application to low-energy devices.
Innovation Solution
A lithium-ion battery design featuring a three-dimensional conducting porous foam current collector with an intermetallic anode and a solid-state electrolyte, where the cathode material fills the pores of the anode, reducing Li-ion diffusion paths and maintaining high energy densities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If thin layers are used to compensate for slow solid-state diffusion, then Li-ion diffusion rate is improved, but energy density is reduced
Solution Approach 1:
The patent transitions from planar two-dimensional electrode geometry to a three-dimensional interpenetrating structure. The cathode and anode are arranged as interdigitated three-dimensional networks with the electrolyte filling the spaces between them, creating multiple diffusion pathways and significantly reducing Li-ion transport distances while maintaining large active material volumes for high energy density
Solution Approach 2:
The patent employs porous three-dimensional electrode structures where the cathode and anode are formed as interconnected porous networks. This porosity allows the electrolyte to penetrate deeply into the electrode interiors, creating short diffusion paths from the electrolyte to active material particles throughout the volume, thereby achieving fast Li-ion diffusion rates without sacrificing energy density
2Ease of manufacture
If conventional line-of-sight fabrication techniques are used, then manufacturing is simplified, but energy density is reduced due to planar geometry
Solution Approach 1:
The patent moves beyond conventional planar two-dimensional battery construction to a three-dimensional interpenetrating architecture. This dimensional transition enables significantly higher energy density by packing more active material into the same footprint while maintaining manufacturability through adapted fabrication processes that can handle three-dimensional structures
3Reliability
If Li-ions must travel large distances between macroscopically separated electrodes, then electrode safety is improved, but diffusion rate is reduced
Solution Approach 1:
The patent uses porous three-dimensional electrode structures that allow electrolyte penetration throughout the electrode volume. This creates numerous short diffusion pathways from the electrolyte to active material particles, enabling fast Li-ion transport rates while the three-dimensional interdigitated arrangement maintains adequate physical separation between cathode and anode for safety
Solution Approach 2:
By transitioning to three-dimensional interpenetrating electrodes, the patent reduces Li-ion transport distances from macroscopic separations to microscopic pathways through the porous structure, dramatically improving diffusion rates while the interdigitated geometry maintains safe electrode separation
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 design enhances Li-ion diffusion rates and energy densities, improving safety and enabling the use of solid-state batteries in applications requiring high energy and power densities, such as electric vehicles.
Implementation Method 1
a solid-state electrolyte conformally coated onto the anode for providing high resistance to electrical current and lithe resistance to the passage of lithium ions
Implementation Method 2
cathode material filling the pores in the coated anode... enhancing Li-ion diffusion rates by reducing the diffusion path length between the electrodes
Data Source
AI summary
A lithium-ion battery including an electrodeposited anode material having a micron-scale, three-dimensional porous foam structure separated from interpenetrating cathode material that fills the void space of the porous foam structure by a thin solid-state electrolyte which has been reductively polymerized onto the anode material in a uniform and pinhole free manner, which will significantly reduce the distance which the Li-ions are required to traverse upon the charge/discharge of the battery cell over other types of Li-ion cell designs, and a procedure for fabricating the battery are described. The interpenetrating three-dimensional structure of the cell will also provide larger energy densities than conventional solid-state Li-ion cells based on thin-film technologies. The electrodeposited anode may include an intermetallic composition effective for reversibly intercalating Li-ions.