3D-VSe2@CN Composite Anode for Potassium Ion Batteries

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Developing a reversible electrode material for potassium ion batteries is challenging due to the large radius of potassium ions, leading to issues such as poor conductivity and rapid capacity decrease in vanadium diselenide (VSe2) materials prepared by hydrothermal or solvothermal methods, which result in impurities and poor crystal structure.

Innovation Solution

A 3D sponge structured carbonitride coated VSe2 composite (3D-VSe2@CN) is prepared using a solvothermal method with a NaCl template, citric acid as a carbon source, and melamine as a nitrogen source, enhancing the electrochemical performance by inhibiting material volume expansion and side reactions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If hydrothermal or solvothermal method is used to prepare VSe2 material, then yield is improved, but product purity and crystal structure quality deteriorate

Engineering Contradiction:

ImproveyieldVSAvoidcrystal structure quality

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies composite materials principle by combining VSe2 with carbon and nitrogen-containing compounds to form a composite structure. This composite approach allows the material to benefit from both VSe2's high yield production and the structural benefits of carbon/nitrogen compounds, resolving the contradiction between yield and crystal structure quality.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent utilizes porous materials principle by creating a 3D porous composite structure that combines VSe2 with carbon-nitrogen compounds. The porous structure provides improved crystal arrangement and prevents re-stacking, thereby maintaining high yield while improving crystal structure quality and reducing impurities.

Inventive Principle:

Principle #31Porous materials

2Quantity of substance

If conventional VSe2 material is used as anode, then initial capacity is achieved, but cycle stability deteriorates due to re-stacking and capacity decrease

Engineering Contradiction:

ImprovecapacityVSAvoidcycle stability

Core Design Contradiction:

Quantity of substanceVSDuration of action of stationary object

Solution Approach 1:

The patent applies flexible shells and thin films principle by coating VSe2 with a carbon-nitrogen compound layer. This thin film coating prevents re-stacking of VSe2 layers and maintains structural integrity during charging-discharging cycles, thereby improving cycle stability while preserving capacity.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The patent uses composite materials principle by creating a VSe2@C-N composite structure where the carbon-nitrogen compound forms a stable outer layer. This composite structure prevents capacity decrease over cycles by protecting the inner VSe2 from degradation and re-stacking, thus improving duration of action.

Inventive Principle:

Principle #40Composite materials

3Device complexity

If VSe2 material with poor conductivity is used, then material simplicity is maintained, but electrochemical performance deteriorates

Engineering Contradiction:

Improvematerial structure simplicityVSAvoidelectrochemical performance

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent applies composite materials principle by combining conductive carbon-nitrogen compounds with VSe2. The carbon-nitrogen compound provides enhanced electrical conductivity while the VSe2 core maintains the desired material simplicity. This composite approach improves electrochemical performance without significantly increasing structural complexity.

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 3D-VSe2@CN composite improves the rate capability and cycle stability of the anode material, maintaining capacity and structural integrity during charging and discharging processes.

Implementation Method 1

The 3D-VSe2@CN composite is prepared by combination of the solvothermal method and the NaCl template method

Methodology Applied

Scientific EffectSolvothermal method:

Implementation Method 2

raising the temperature of the black powers obtained in step 9 to 180 ̃300° C. from 25° C. at 1 ̃5° C./min under the inert atmosphere, carrying out heat preservation for 1 ̃5 h; then raising the temperature to 450 ̃800° C. at 1 ̃5° C./min, and carrying out heat preservation for 2 ̃5 h

Methodology Applied

Scientific EffectPyrolysis: Pyrolysis

Data Source

PatentUS20220380214A1METHOD FOR PREPARING 3D CARBONITRIDE COATED VSE2 COMPOSITE (3D-VSe2@CN)

Publication Date: 2022.12.01 GUANGDONG UNIV OF TECH

AI summary

The disclosure relates to a method for preparing a 3D sponge structured carbonitride coated VSe2 composite (3D-VSe2@CN), belonging to the technical fields of electrode materials and preparation of batteries. In the disclosure, carbon, nitrogen and VSe2 are composited by using NaCl as a template so as to construct a 3D sponge structured carbonitride coated VSe2 composite. The 3D sponge structure can increase the structure stability of the material in the cyclic process, and the carbocanitride can increase the electron conductivity and activity sites of the material, so as to allow easier diffusion of potassium ions. Meanwhile, the stable structure can cause the clustering of VSe2 all the time. Thus, the prepared composite has good and stable rate capability and cycle stability. The process method is simple, low in cost, environmental-friendly, and suitable for large-scale industrial production.