CMOS-Compatible Solid-State Battery Fabrication via Lithiation

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Solution Overview

Problem

Existing methods for fabricating solid-state thin film Li-ion batteries are time-consuming and not compatible with CMOS processing, leading to contamination issues and complexity in material preparation.

Innovation Solution

A method involving the deposition of an initial Li-free layer stack on a substrate, followed by a lithiation step using a Li compound to form a battery half-cell or cell stack with a reduced number of process steps, including a single annealing step, which is compatible with CMOS processing and reduces material complexity and contamination risks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional separate preparation methods are used for battery components, then material quality can be maintained, but the fabrication process becomes time-consuming and complex

Engineering Contradiction:
Improvefabrication speedVSAvoidprocess complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent combines multiple separate component preparation steps into a single co-deposition process. The battery components (electrodes, electrolyte, current collectors) are deposited simultaneously in one continuous process rather than being prepared separately and assembled, thereby reducing fabrication time and process complexity while maintaining material quality

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The deposition process is designed to perform multiple functions simultaneously: depositing different battery components, forming current collectors, creating electrolyte layers, and assembling the battery structure all in one process step, eliminating the need for separate preparation and assembly operations

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of manufacture

If Li-containing materials are used in CMOS processing facilities, then battery fabrication can proceed, but serious contamination issues arise

Engineering Contradiction:
Improveprocess compatibilityVSAvoidcontamination
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent segments the fabrication process into two distinct parts: first, depositing Li-free battery components in the CMOS facility; second, adding Li-containing materials in a separate post-processing step outside the CMOS facility. This segmentation eliminates Li contamination in the CMOS environment while still enabling complete battery fabrication

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The Li-containing step is extracted and removed from the CMOS processing sequence, to be performed separately after the Li-free components are deposited in the CMOS facility. This extraction eliminates the contamination problem while preserving the benefits of CMOS-compatible fabrication for the majority of the battery structure

Inventive Principle:
Principle #2Taking out (Extraction)

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 method simplifies the fabrication process, reduces material usage, enhances cyclic performance, and allows for high-throughput production of thin film batteries with reduced safety risks and lower costs, while maintaining compatibility with CMOS processing.

Implementation Method 1

performing a thermal treatment, thereby inducing a solid-state reaction between the Li compound and the material compounds of the Li-free layers of the initial layer stack

Methodology Applied
Scientific EffectSolid-state reaction:

Implementation Method 2

depositing on a substrate an initial layer stack comprising a first Li-free layer comprising a first electrode material compound and a second Li-free layer comprising an electrolyte material compound

Methodology Applied
Scientific EffectPhysical vapor deposition: Physical Vapour Deposition

Implementation Method 3

The layer comprising the Li compound may for example be provided by solution processing, such as for example by spin coating

Methodology Applied
Scientific EffectSpin coating: Spin Coating

Implementation Method 4

performing a thermal treatment, thereby inducing a solid-state reaction between the Li compound and the material compounds of the Li-free layers of the initial layer stack

Methodology Applied
Scientific EffectThermal treatment: Heat Treatment

Data Source

PatentEP3091601B1Method for fabricating solid-state thin film batteries
Publication Date: 2018.01.31 INTERUNIVERSITAIR MICRO ELECTRONICS CENT (IMEC VZW)
  • EP3091601B1 patent drawingFigure 1(a)~2
  • EP3091601B1 patent drawingFigure 3(a)~4
  • EP3091601B1 patent drawingFigure 5(a)~5(c)

AI summary

A method is provided for fabricating a thin film solid-state Li-ion battery comprising a first electrode layer, a solid electrolyte layer and a second electrode layer. The method comprises: depositing (101) on a substrate an initial layer stack comprising a first Li-free layer comprising a first electrode material compound and a second Li-free layer comprising an electrolyte material compound; and afterwards performing a lithiation step (102), the lithiation step comprising incorporating Li in the first layer and in the second layer, thereby forming a stack of a first electrode layer and a solid electrolyte layer. The initial layer stack may further comprise a third Li-free layer comprising a second electrode material compound. By performing the lithiation step, Li is also incorporated in the third layer, such that a stack of a first electrode layer, a solid electrolyte layer and a second electrode layer is formed.