Solid state battery, ceramic electrolyte structure, and methods of making
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Solution Overview
Problem
Conventional solid state batteries with dense ceramic electrolytes suffer from low energy and power density, increased manufacturing costs, and a high tendency for lithium dendrite formation and void formation, leading to reduced safety and performance.
Innovation Solution
The development of a porous ceramic-based solid electrolyte structure with an interconnected ceramic matrix and a network of open pores, along with an intermetallic layer disposed on the porous electrolyte structure, to enhance safety, reduce dendrite and void formation, and increase energy and power density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thick dense ceramic-based electrolyte is used to maintain structural integrity, then safety is improved, but energy density is reduced
Solution Approach 1:
The patent applies porous ceramic materials for the electrolyte layer, where the porous structure allows for thinner electrolyte layers while maintaining mechanical integrity through the porous network. The pores can also accommodate volume changes during lithium deposition and stripping, preventing fracture in thin electrolytes. This enables reduced electrolyte thickness (improving energy density) while maintaining structural integrity (safety).
Solution Approach 2:
The patent uses composite structures combining ceramic materials with porous architectures and potentially interfacial layers. The composite nature allows the electrolyte to simultaneously achieve thin thickness (for high energy density) and sufficient mechanical strength (for safety), as the composite structure distributes stress and prevents catastrophic failure.
2Reliability
If a thick dense ceramic-based electrolyte is used to maintain structural integrity, then safety is improved, but manufacturing costs increase
Solution Approach 1:
Porous ceramic electrolytes can be manufactured using techniques like foam templating, space holder methods, or direct sintering of porous precursors, which are more cost-effective than producing thick dense ceramics. The porous structure reduces material consumption and allows for thinner, lighter electrolyte layers, reducing both material costs and manufacturing complexity.
3Productivity
If higher current densities are used to reduce charge time, then productivity is improved, but the electrolyte undergoes fatigue and fracture
Solution Approach 1:
The porous ceramic electrolyte structure accommodates volume changes during high-rate lithium deposition and stripping through its porous architecture. The pores provide buffer space for expansion and contraction, preventing mechanical fatigue and fracture that would occur in dense electrolytes under high current densities. This enables safe operation at higher charging rates.
Solution Approach 2:
The patent changes the physical parameters of the electrolyte from dense to porous structure, which fundamentally alters its mechanical response to volumetric changes. The porous structure has higher tolerance for strain and stress, allowing the battery to operate at higher current densities without electrolyte failure.
4Ease of manufacture
If small gaps are present between the solid electrolyte and current collector, then ease of assembly is improved, but interfacial contact is lost leading to increased resistance
Solution Approach 1:
The porous electrolyte structure can deform and conform to the current collector surface, filling small gaps and maintaining intimate interfacial contact. The porous network provides mechanical compliance that allows the electrolyte to adapt to surface irregularities, ensuring continuous electrical and ionic contact while still allowing for assembly tolerances.
Data Source
AI summary
A porous electrolyte structure for a solid state battery is provided. The porous electrolyte structure includes an inter-metallic layer disposed on a surface and has an interconnected ceramic matrix with a network of open pores disposed throughout a thickness of the porous electrolyte structure. The porous electrolyte structure includes a porosity of about 10% by volume to about 80% by volume. A solid state battery cell including the porous electrolyte structure and a method of making the solid state battery cell are also provided.