Electrolyte-Free LixSi/Si Anode Electrode With Lithium Compensation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

All-solid-state battery cells with silicon anode electrodes experience rapid active lithium loss due to side reactions with the PTFE binder, leading to low coulombic efficiency and reduced energy density.

Innovation Solution

Incorporating excess lithium into the anode current collector to form LixSi/Si active materials, amorphous carbon, and lithium fluoride, which compensates for lithium loss during the formation process, forming a robust electrolyte-free anode electrode.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If silicon particles and PTFE binder are used in the anode active material layer, then the anode electrode can be formed, but rapid active lithium loss occurs due to side reactions with PTFE binder

Engineering Contradiction:

Improvecoulombic efficiencyVSAvoidactive lithium loss

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

The patent applies preliminary action by incorporating excess lithium into the anode current collector before the formation process. This pre-positioned lithium serves as a reservoir that compensates for the lithium consumed by PTFE binder side reactions during initial cycling, thereby maintaining high coulombic efficiency throughout the battery's operational life.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes the parameter of lithium content in the anode current collector by incorporating excess lithium (typically 5-50 μm thickness) beyond the stoichiometric amount needed for LixSi formation. This parameter change ensures that sufficient lithium remains available after PTFE consumption, resolving the contradiction between using PTFE binder and maintaining coulombic efficiency.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If excess lithium is incorporated into the anode current collector, then lithium loss during formation is compensated, but the device structure becomes more complex

Engineering Contradiction:

Improvelithium compensation capabilityVSAvoidanode current collector structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the function of the anode current collector with the function of lithium reservoir by incorporating excess lithium directly into the current collector structure. This integration eliminates the need for separate lithium compensation mechanisms, thereby reducing overall device complexity while maintaining lithium compensation capability.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The anode current collector is designed to serve multiple functions: electrical conduction, mechanical support, and lithium reservoir. By making the current collector multi-functional through lithium incorporation, the patent avoids adding separate components for lithium compensation, thus managing device complexity while achieving reliable lithium compensation.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of manufacture

If electrolyte mixing process is eliminated, then manufacturing is simplified and material costs are reduced, but ensuring high lithium-ion conduction becomes more challenging

Engineering Contradiction:

Improvemanufacturing process simplicityVSAvoidlithium-ion conduction

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent extracts the electrolyte from the anode electrode structure, creating an electrolyte-free design. By removing the electrolyte mixing process, manufacturing is simplified and material costs are reduced. The lithium-ion conduction is maintained through the solid-state LixSi active material and amorphous carbon matrix that provide direct conduction pathways without requiring liquid electrolyte.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs amorphous carbon and LixSi materials with inherent porous or interconnected structures that facilitate lithium-ion transport. These porous materials provide sufficient ion conduction pathways without requiring electrolyte, thereby maintaining reliability while enabling electrolyte-free manufacturing.

Inventive Principle:

Principle #31Porous materials

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

Enhances energy density, reduces material costs, and simplifies manufacturing by eliminating the electrolyte mixing process while maintaining high lithium-ion conduction.

Implementation Method 1

the lithium reacts with the anode active material layer to form amorphous carbon, lithium fluoride, and LixSi in the active material layer prior to formation

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 2

the lithium reacts with the anode active material layer to form amorphous carbon, lithium fluoride, and LixSi in the active material layer

Methodology Applied

Scientific EffectAlloying reaction: Chemical Bonding

Data Source

PatentUS20250336961A1ELECTROLYTE-FREE LIxSI/SI ANODE ELECTRODE FOR ALL-SOLID-STATE BATTERY CELL

Publication Date: 2025.10.30 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A method for manufacturing a battery cell includes providing an anode active material layer including silicon particles and PTFE binder; and pressing the anode active material layer and an anode current collector together to form an anode electrode. The anode current collector comprises a composite material comprising a first material and lithium arranged on at least one side of the first material and in contact with the anode active material layer.