Concave Silicon Anode Structure for Solid-State Battery Cycling

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Solution Overview

Problem

Conventional all-solid-state batteries with sheet-type silicon anode electrodes face limitations in delivered rate capability and cycling performance, requiring enhancements to accommodate silicon expansion and contraction during charging and discharging.

Innovation Solution

The use of a silicon anode electrode with concave spherical surfaces deposited using pulsed DC magnetron sputtering, which increases the silicon/electrolyte interface area, reduces stress, and simplifies the fabrication process by eliminating the need for binders and solvents, while the sulfide electrolyte accommodates the anode's expansion and contraction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If sheet-type silicon anode electrodes are used, then the fabrication process is simple, but the rate capability and cycling performance are limited

Engineering Contradiction:

Improvefabrication process simplicityVSAvoidrate capability

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The patent applies spherical morphology to silicon anode particles, creating concave spherical structures instead of flat sheet-type electrodes. This curvature increases the surface area to volume ratio, enhancing the silicon/electrolyte interface area and improving rate capability while maintaining a straightforward deposition process through pulsed DC magnetron sputtering

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Device complexity

If sheet-type silicon anode electrodes are used, then the structure is simple, but the cycling performance deteriorates

Engineering Contradiction:

Improveelectrode structure complexityVSAvoidcycling performance

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The concave spherical structure provides superior stress management during lithium insertion and extraction cycles. The spherical geometry distributes mechanical stress uniformly, accommodating silicon expansion and contraction more effectively than flat sheets, thereby improving cycling performance and reliability

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The concave spherical structures create an increased surface area with inherent porosity, providing more active sites for lithium insertion and improving electrolyte penetration. This porous-like structure enhances cycling performance by facilitating better ion transport and stress distribution

Inventive Principle:

Principle #31Porous materials

3Area of stationary object

If conventional sheet-type anodes are used, then the interface area is limited, but the fabrication process is simpler

Engineering Contradiction:

Improvesilicon/electrolyte interface areaVSAvoidpower capability

Core Design Contradiction:

Area of stationary objectVSProductivity

Solution Approach 1:

The concave spherical structures dramatically increase the silicon/electrolyte interface area compared to flat sheet-type anodes. The curved surfaces provide enhanced contact with the electrolyte, creating more active sites for electrochemical reactions and improving power capability

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent transitions from a two-dimensional flat sheet structure to a three-dimensional concave spherical structure. This dimensional change significantly increases the surface area available for electrochemical reactions, enhancing the interface area between silicon and electrolyte without proportionally increasing the overall electrode thickness

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 configuration enhances the power capability and cycling stability of the battery, offering improved capacity retention and rate capability, as demonstrated by increased surface area and efficient stress management.

Implementation Method 1

A silicon layer is arranged on the anode current collector and includes a plurality of concave spherical surfaces... which increases the silicon/electrolyte interface area

Methodology Applied

Scientific EffectSurface area enhancement through concave spherical structures: Geometry

Implementation Method 2

The silicon layer is deposited using DC magnetron sputtering

Methodology Applied

Scientific EffectMagnetron sputtering: Sputtering

Implementation Method 3

the sulfide electrolyte accommodates the anode's expansion and contraction

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Data Source

PatentUS20240379997A1All-solid-state battery including silicon anode with concave spherical structures

Publication Date: 2024.11.14 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A solid-state battery cell includes a cathode electrode includes a cathode current collector and a cathode active layer arranged on the cathode current collector and including cathode active material and a solid electrolyte. A separator layer comprises the solid electrolyte. An anode layer comprises an anode current collector and a silicon layer arranged on the anode current collector and including a plurality of concave spherical surfaces.