Nitrate-Coated Negative Electrode for Lithium Dendrite Suppression

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Solution Overview

Problem

Lithium-ion secondary batteries face issues with lithium dendrite growth during cycling, which can lead to thermal runaway and reduce battery cycle life and safety.

Innovation Solution

Incorporating a nitrate, such as magnesium nitrate, into the negative film layer of the battery, which suppresses the growth of lithium dendrites by diffusing into the electrolyte and forming an alloy with lithium, thereby lowering the diffusion energy barrier.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If lithium-ion secondary batteries are charged and discharged for multiple cycles, then the battery provides sustained energy storage and power delivery, but lithium precipitates on the electrode and grows into lithium dendrites that puncture the separator and cause thermal runaway

Engineering Contradiction:

Improvecycle lifeVSAvoidsafety performance

Core Design Contradiction:

Duration of action of moving objectVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-coating the negative current collector with a negative film layer containing nitrate compounds (such as lithium nitrate, sodium nitrate, potassium nitrate, calcium nitrate, or magnesium nitrate) before the battery enters cycling operation. This pre-prepared layer serves as a reservoir that gradually releases nitrate ions during charging and discharging cycles, proactively suppressing lithium dendrite formation before they can grow to dangerous sizes and puncture the separator, thus maintaining safety performance throughout the battery's cycle life.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces nitrate compounds as an intermediary substance between the negative current collector and the electrolyte solution. The nitrate layer acts as a mediator that interferes with the direct interaction between lithium ions and the electrode surface, preventing lithium precipitation and dendrite growth. The nitrate ions compete with lithium ions for insertion sites and form a protective interface that suppresses harmful lithium deposition, thereby resolving the contradiction between extended cycling and maintained safety.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If lithium dendrites grow on the electrode during cycling, then the battery continues to operate, but the dendrites puncture the separator and cause thermal runaway

Engineering Contradiction:

Improvecontinuous operationVSAvoidthermal runaway risk

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary anti-action by incorporating nitrate compounds into the negative film layer that actively counteract the formation of lithium dendrites during battery operation. The nitrate ions released during cycling create a protective environment at the electrode surface that prevents lithium precipitation and dendrite nucleation, thereby preemptively neutralizing the harmful factor before it can develop into thermal runaway conditions, allowing continuous operation without safety compromise.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The patent converts the potentially harmful presence of nitrate compounds into a beneficial protective mechanism. While nitrate salts might seem like inert additives, they actually serve as a protective agent that suppresses lithium dendrite formation. The nitrate ions interact with lithium ions during cycling to prevent harmful deposition, transforming what could be a neutral or harmful substance into a protective element that enhances safety while maintaining continuous operation.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 addition of nitrate to the negative film layer effectively prevents lithium dendrite formation, maintaining battery safety and extending cycle life even after multiple charge and discharge cycles.

Implementation Method 1

suppresses the growth of lithium dendrites by diffusing into the electrolyte and forming an alloy with lithium

Methodology Applied

Scientific EffectDiffusion: Diffusion

Implementation Method 2

forming an alloy with lithium, thereby lowering the diffusion energy barrier

Methodology Applied

Scientific EffectAlloy formation:

Data Source

PatentUS20250038189A1Secondary battery, method for preparing same, and electrical device containing same

Publication Date: 2025.01.30 CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED

AI summary

This application provides a secondary battery, including a negative electrode plate. The negative electrode plate includes a negative current collector and a negative film layer disposed on at least one surface of the negative current collector. The negative film layer contains a nitrate. The secondary battery of this application can avoid generation of lithium dendrites during cycling. This application further provides an electrical device containing the secondary battery.