Printable Lithium Interface Layer for Solid-State Battery Contact
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Solution Overview
Problem
Lithium-ion batteries face a significant capacity loss due to the formation of a passivation film on the anode during the first charge cycle, resulting in irreversible capacity loss and reduced energy density, which affects their performance and safety in applications like electric vehicles.
Innovation Solution
A solid-state battery with prelithiated components using a printable lithium composition, comprising lithium metal powder, a polymer binder, and a rheology modifier, applied as an interface layer or anode material to enhance energy density and safety, and improve manufacturability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If lithium-ion batteries use conventional anode materials, then the battery can operate safely with good cyclability, but the specific capacity is limited due to irreversible capacity loss from SEI formation
Solution Approach 1:
The patent applies preliminary action by pre-lithiating the anode with stabilized lithium metal powder before battery operation. This pre-added lithium compensates for the irreversible capacity loss that occurs during SEI formation, ensuring that the battery maintains its full specific capacity throughout cycling without the limitations of conventional anode materials
2Quantity of substance
If stabilized lithium metal powder is used to pre-lithiate the anode, then the specific capacity is improved, but the lithium metal content decays due to reaction with air over time
Solution Approach 1:
The patent employs composite materials by creating a stabilized lithium metal powder where lithium metal is combined with a stabilizing agent (such as fluorinated hydrocarbon coating). This composite structure maintains the high specific capacity benefits of lithium metal while preventing its decay through reaction with air, solving the stability problem
Solution Approach 2:
The stabilized lithium metal powder is designed to create an inert protective environment around the reactive lithium metal content. The stabilizing coating acts as a barrier that prevents direct contact between lithium metal and atmospheric moisture/oxygen, allowing the battery to maintain high capacity without degradation from air reactions
3Reliability
If coatings such as fluorine, wax, phosphorus or polymer are applied to lithium metal powder, then the stability against air reaction is improved, but the manufacturing complexity and process difficulty increase
Solution Approach 1:
The patent applies parameter changes by optimizing the coating thickness, composition ratios, and processing parameters to achieve stable lithium metal powder with simplified manufacturing. By carefully controlling these parameters, the patent reduces the complexity of the coating process while maintaining the stability benefits, making the manufacturing more feasible
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 use of a printable lithium composition in solid-state batteries increases energy density, improves safety, and enhances manufacturability by optimizing the interface between the anode and electrolyte, reducing impedance growth and maintaining high capacity retention across cycles.
Implementation Method 1
lithium metal can be stabilized by passivating the metal powder surface with carbon dioxide or by applying a coating such as fluorine, wax, phosphorus or a polymer
Implementation Method 2
lithium metal powder, which has been stabilized by passivating the metal powder surface
Implementation Method 3
lithium-ions are transferred from the anode to the cathode through the electrolyte when the secondary battery is being discharged
Implementation Method 4
electrons are collected from the anode and pass to the cathode through an external circuit
Implementation Method 5
When the secondary battery is being charged, or recharged, the lithium-ions are transferred from the cathode to the anode through the electrolyte
Implementation Method 6
lithium moves from the cathode to the anode active material. The lithium moving from the cathode to the anode reacts with an electrolyte material at the surface of the graphite anode, causing the formation of a passivation film on the anode
Data Source
AI summary
A battery comprising a lithium metal anode; a solid electrolyte; a cathode; and at least one interface layer between a surface of the cathode and a surface of the solid electrolyte, the interface layer formed of a printable lithium composition comprised of lithium metal powder, a polymer binder compatible with the lithium metal powder, a rheology modifier compatible with the lithium metal powder, and a solvent compatible with the lithium metal powder and with the polymer binder, wherein the interface layer improves the uniformity of the surface of the solid electrolyte thereby optimizing contact between the surface of the cathode and the surface of the solid electrolyte for better battery performance.