SiOC-Graphite Anode with Lithium Layer for First-Cycle Efficiency

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Solution Overview

Problem

Silicon-based negative electrode materials face issues such as low conductivity, volume swelling, and the formation of an unstable solid electrolyte interphase (SEI) film, leading to degraded electrochemical performance and capacity fading, which limits their application. The SiOC material, while reducing volume swelling, has low first-cycle coulombic efficiency due to irreversible lithium storage.

Innovation Solution

Incorporating a SiOC material with graphite and a lithium-containing layer containing stabilized lithium metal powder in the negative electrode active substance layer, activated by the electrolyte, to provide additional active lithium ions and improve electrochemical performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If SiOC material is used to reduce volume swelling, then volume swelling is reduced, but first-cycle coulombic efficiency decreases due to irreversible lithium storage

Engineering Contradiction:

Improvevolume swellingVSAvoidfirst-cycle coulombic efficiency

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The patent recovers lithium ions by adding a lithium-containing layer that releases lithium during the first discharge, compensating for the lithium irreversibly consumed by SiOC material during first charge, thereby improving first-cycle coulombic efficiency

Inventive Principle:

Principle #34Discarding and recovering

Solution Approach 2:

The patent uses a composite negative electrode structure combining SiOC material with graphite and a lithium-containing layer, where each component serves a specific function: SiOC provides low volume swelling, graphite provides stable lithium storage, and the lithium-containing layer compensates for irreversible lithium consumption

Inventive Principle:

Principle #40Composite materials

2Quantity of substance

If silicon-based negative electrode materials are used to achieve high gram capacity, then gram capacity is improved, but conductivity decreases and volume swelling increases

Engineering Contradiction:

Improvegram capacityVSAvoidlow conductivity and volume swelling

Core Design Contradiction:

Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent employs a composite material system combining SiOC (silicon-oxygen-carbon) with graphite and conductive carbon materials, where SiOC retains high capacity characteristics while graphite and carbon provide electrical conductivity and structural stability, reducing volume swelling during cycling

Inventive Principle:

Principle #40Composite materials

3Quantity of substance

If silicon negative electrode material is used, then high capacity is achieved, but cycling stability deteriorates due to pulverization and loss of electrical contact

Engineering Contradiction:

ImprovecapacityVSAvoidcycling stability

Core Design Contradiction:

Quantity of substanceVSDuration of action of stationary object

Solution Approach 1:

The patent uses a carbon-coated structure and binder system that forms a flexible protective matrix around the silicon-based active material, accommodating volume expansion and contraction during cycling while maintaining electrical contact and preventing pulverization

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The composite structure of SiOC, graphite, and conductive carbon creates a mechanically robust electrode that maintains structural integrity during volume changes, ensuring sustained electrical contact between active material and current collector over multiple cycles

Inventive Principle:

Principle #40Composite 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 the first-cycle coulombic efficiency and energy density of the electrochemical apparatus by compensating for irreversible lithium consumption in the SiOC material, thereby improving the overall battery performance.

Implementation Method 1

the SiOC material in the active material layer and the stabilized lithium metal powder in the lithium-containing layer can be activated by contact with the electrolyte, to provide more active lithium ions for the electrochemical apparatus

Methodology Applied

Scientific EffectElectrochemical activation: Electrolysis

Data Source

PatentUS12562378B2Electrochemical apparatus and electronic apparatus

Publication Date: 2026.02.24 NINGDE AMPEREX TECHNOLOGY LTD

AI summary

An electrochemical apparatus includes a positive electrode plate and a negative electrode plate, the negative electrode plate includes a negative electrode current collector and a negative electrode active substance layer disposed on a surface of the negative electrode current collector; the negative electrode active substance layer includes an active material layer and a lithium-containing layer provided on a surface of the active material layer; and the active material layer includes a SiOC material and graphite. The negative electrode material provided in this application can improve the first-cycle coulombic efficiency and energy density of the electrochemical apparatus.