Negative Electrode Sheet with Radial Protrusions

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Solution Overview

Problem

Lithium-ion battery electrode materials face issues with active material detachment due to repeated expansion and contraction, leading to shortened service life, and antimony's high reversible specific capacity is compromised by volume changes during reaction, resulting in poor electrical-cycling-performance.

Innovation Solution

A negative electrode sheet with a conductive fiber cloth current collector featuring radially arranged needle-shaped protrusions made of basic cobalt nickel carbonate (NiCo(CO3)0.5OH) and an active material layer of antimony trioxide (Sb2O3) formed on these protrusions, enhancing surface area and adhesion, and a cladding layer to prevent pulverization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If active materials are coated on current collector surface, then battery capacity is improved, but active materials detach during expansion and contraction

Engineering Contradiction:

Improvebattery capacityVSAvoidactive material adhesion

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent applies preliminary action by forming a support layer with needle-shaped protrusions on the current collector surface before coating the active material. This preliminary structural preparation creates anchoring features that prevent detachment during subsequent expansion and contraction cycles, while still allowing full utilization of active material capacity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The support layer with needle-shaped protrusions creates a porous, three-dimensional structure that provides both mechanical anchoring and increased surface area for active material deposition. This porous architecture accommodates volume changes while maintaining strong adhesion and electrical conductivity.

Inventive Principle:

Principle #31Porous materials

2Quantity of substance

If antimony trioxide is used as active material, then reversible specific capacity is improved, but volume changes cause pulverization

Engineering Contradiction:

Improvereversible specific capacityVSAvoidstructural integrity

Core Design Contradiction:

Quantity of substanceVSStrength

Solution Approach 1:

The patent applies local quality by creating regions with different structural properties - the needle-shaped protrusions provide localized mechanical support and stress distribution, while the active material coating provides electrochemical function. This localized structural differentiation allows antimony trioxide to maintain high capacity while resisting pulverization through distributed stress management.

Inventive Principle:

Principle #3Local quality

3Reliability

If support layer with needle-shaped protrusions is formed, then adhesion and surface area are improved, but manufacturing complexity increases

Engineering Contradiction:

Improveactive material adhesionVSAvoidsupport layer structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The support layer with needle-shaped protrusions acts as an intermediary between the current collector and the active material. This intermediate structure simplifies the overall manufacturing by providing a pre-fabricated adhesion-enhancing substrate, eliminating the need for complex coating processes or post-treatments to improve bonding.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 design improves electrochemical performance, charging and discharging speed, and cycling stability by maintaining active material adhesion and flexibility, thereby extending battery life.

Implementation Method 1

The support layer is formed on a surface of the conductive fiber cloth and includes multiple protruding units, where each of the multiple protruding units includes multiple needle-shaped protrusions

Methodology Applied

Scientific EffectPhysical anchoring: Mechanical Fastener

Implementation Method 2

since active materials on a surface of a current collector may repeatedly expand and contract during embedding/de-embedding of lithium ions

Methodology Applied

Scientific EffectExpansion and contraction: Thermal Expansion

Implementation Method 3

The conductive fiber cloth serves as a current collector of the negative electrode sheet

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentUS11670761B1Negative electrode sheet and manufacturing method thereof and battery

Publication Date: 2023.06.06 HITHIUM TECH HK LTD

AI summary

A negative electrode sheet and a manufacturing method thereof and a battery are provided in the disclosure. The negative electrode sheet includes a conductive fiber cloth, a support layer, and an active material layer. The conductive fiber cloth serves as a current collector of the negative electrode sheet. The support layer is formed on a surface of the conductive fiber cloth and includes multiple protruding units, where each of the multiple protruding units includes multiple needle-shaped protrusions, and the multiple needle-shaped protrusions of each protruding unit are arranged radially. The active material layer includes multiple active portions, where each of the multiple active portions is formed on a surface of one of the multiple needle-shaped protrusions, and different active portions are formed on surfaces of different needle-shaped protrusions.