Amorphous Nickel-Phosphorus Anode for Rechargeable Battery

Solution Overview

Problem

Nickel surfaces in rechargeable batteries exhibit low hydrogen overvoltage and corrosion resistance, leading to self-discharge and capacity loss when attempting to deposit zinc, as they behave as cathodes and cause rapid dissolution of zinc deposits under alkaline conditions.

Innovation Solution

Electroless nickel plating with phosphorous is used to modify the nickel surface, reducing hydrogen overvoltage and allowing zinc deposition while maintaining resistance to severe battery reversal, using a reducing agent like hydrated sodium hypophosphite to co-deposit phosphorous with nickel, resulting in an amorphous nickel-phosphorus alloy coating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If nickel surface is used for zinc deposition, then charge acceptance is improved, but self-discharge and capacity loss occur due to low hydrogen overvoltage and corrosion resistance

Engineering Contradiction:

Improvecharge acceptanceVSAvoidself-discharge and capacity loss

Core Design Contradiction:

Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The invention changes the surface parameters of nickel by coating it with amorphous nickel-phosphorus alloy. This coating modifies the surface properties to increase hydrogen overvoltage and reduce corrosion resistance, thereby preventing self-discharge and capacity loss while maintaining charge acceptance capabilities.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite structure consisting of a nickel substrate coated with amorphous nickel-phosphorus alloy. This composite material combines the beneficial properties of nickel (charge acceptance) with the protective properties of the phosphorus-containing coating (reduced self-discharge and capacity loss).

Inventive Principle:

Principle #40Composite materials

2Use of energy by moving object

If nickel surface is used for zinc deposition, then charge acceptance is improved, but zinc dissolution occurs due to corrosion resistance

Engineering Contradiction:

Improvecharge acceptanceVSAvoidzinc deposit stability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The invention changes the surface parameters of nickel by coating it with amorphous nickel-phosphorus alloy. This coating modifies the surface properties to increase hydrogen overvoltage and reduce corrosion resistance, thereby preventing self-discharge and capacity loss while maintaining charge acceptance capabilities.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite structure consisting of a nickel substrate coated with amorphous nickel-phosphorus alloy. This composite material combines the beneficial properties of nickel (charge acceptance) with the protective properties of the phosphorus-containing coating (reduced self-discharge and capacity loss).

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

The modified nickel surface enables charge acceptance and resistance to battery reversal, preventing self-discharge and capacity loss, allowing complete discharge of high-capacity cells even when low-capacity cells are forced into reversal, enhancing the stability and longevity of rechargeable batteries.

Implementation Method 1

Electroless nickel plating with phosphorous is used to modify the nickel surface

Methodology Applied

Scientific EffectElectroless plating: Electroplating

Implementation Method 2

using a reducing agent like hydrated sodium hypophosphite to co-deposit phosphorous with nickel

Methodology Applied

Scientific EffectCo-deposition: Coprecipitation

Implementation Method 3

resulting in an amorphous nickel-phosphorus alloy coating

Methodology Applied

Scientific EffectAmorphous alloy formation:

Data Source

PatentEP3353834B1Electroless plated anode for secondary battery

Publication Date: 2021.08.04 VIZN ENERGY SYSTEMS INC

Figure 1
Figure 2

AI summary

A secondary battery includes an alkaline electrolyte and a negative electrode in contact with the alkaline electrolyte. The negative electrode includes a conductive metal substrate having thereon an amorphous metal alloy coating of nickel and phosphorous.