Dry Solid-State Lithium Cell Films Without High-Temperature Sintering
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Solution Overview
Problem
Solid state electrolytes in lithium-ion batteries face challenges such as low conductivity, limited stability, and poor mechanical properties, which hinder their scalability and integration into high-capacity devices due to the need for high-temperature sintering and brittle film formation.
Innovation Solution
The method involves compressing dry mixtures of electrode and electrolyte materials to form films, including calendering processes, which enables the creation of solid-state electrodes and electrolytes with improved mechanical strength and conductivity, using materials like Li3PS4 glass ceramic and air-stabilizing dopants to enhance stability and ionic conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high temperature sintering is used to consolidate solid state electrolyte films, then interfacial impedance is managed and films are consolidated, but the films become brittle and production is limited to low capacity devices or small disks
Solution Approach 1:
The patent changes the temperature parameter from high temperature sintering to low temperature calendering (below 100°C), fundamentally altering the consolidation mechanism while maintaining effective interfacial contact and managing impedance without compromising mechanical strength
Solution Approach 2:
The patent replaces the thermal field (sintering) with a mechanical field (calendering), using controlled compression and rolling to achieve film consolidation and interfacial contact without the damaging effects of high temperature processing
2Reliability
If conventional high temperature processing is used for solid state electrolytes, then films are consolidated, but production scalability is limited and device capacity is restricted
Solution Approach 1:
The patent changes the processing temperature from high temperature to low temperature (below 100°C), enabling scalable production processes that can handle larger areas and higher volumes without the equipment and material constraints of high temperature processing
Solution Approach 2:
The calendering process can simultaneously process multiple layers (electrode and electrolyte) in a single operation, and can be scaled to produce large-area films continuously, making it universally applicable to various device formats and capacities
3Object-affected harmful factors
If solid state electrolytes are used in lithium ion batteries, then safety is improved by reducing thermal runaway risk, but conductivity is reduced and mechanical properties are poor
Solution Approach 1:
The patent uses composite solid state electrolyte materials combining glass ceramic with conductive additives and binders, achieving a balance between safety and ionic conductivity by leveraging the complementary properties of different materials
Solution Approach 2:
The patent optimizes the composition parameters of the solid state electrolyte (ratios of glass ceramic, conductive additive, and binder) to maximize ionic conductivity while maintaining the safety advantages of solid state 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 approach results in solid-state batteries with enhanced ionic conductivity, mechanical strength, and stability, enabling the production of high-capacity devices with improved cycle life and energy density, comparable to conventional lithium-ion batteries.
Implementation Method 1
compressing an electrode dry mixture to form an electrode film; compressing an electrolyte dry mixture against a surface of the electrode film; calendering the electrode dry mixture; calendering the electrolyte dry mixture against the surface of the electrode film
Data Source
AI summary
Provided are electrodes that include an electrode dry mixture and a dry electrolyte material intermixed with the electrode dry mixture; and a binder intermixed with the electrode dry mixture and the dry electrolyte material, said binder comprising fibrils; the electrode dry mixture, dry electrolyte material, and said binder in the form of a dry electrode film. The electrolyte material may include a glass ceramic and, optionally, an air-stabilizing dopant. The glass ceramic may include Li3PS4. The electrodes may include a composite cathode of the dry electrode film and optionally further include a solid-state electrolyte layer. Also provided are methods for forming the electrodes, optionally where the methods may be applicable for a solvent-free process to form electrodes and electrochemical cells and batteries including the electrodes.