The University of Southampton
University of Southampton Institutional Repository

Applications of metal nitride nanostructures in stabilising high energy and high capacity battery systems

Applications of metal nitride nanostructures in stabilising high energy and high capacity battery systems
Applications of metal nitride nanostructures in stabilising high energy and high capacity battery systems
Applications of metal nitride nanostructures in stabilising high energy and high capacity battery systems were investigated. Sol-gel synthesis routes using tetrakis(dimethylamido)titanium(IV) and a propylamine or ammonia cross linking agent, followed by thermal treatment under NH3 or H2+N2,were developed to produce TiN powders of small crystallite size (<10 nm). The TiN with good conductivity were coated on LiFePO4 cathodes in lithium-ion batteries, which exhibited significantly improved electrochemical performance with a discharge capacity of 159 mA h g-1 at 0.1 C, that is~93% of the theoretical capacity. A literature review of various synthetic routes such as solid-state reactions, hydrothermal/solvothermal synthesis and sol-gel process to produce LiCoPO4 was performed, and various strategies such as surface modification, ion doping, size reduction and morphology control to improve the electrochemical performance of LiCoPO4 were summarised. Olivine-structured LiCoPO4 was prepared via a facile solvothermal synthesis, using various ratios of water/diethylene glycol co-solvent, followed by thermal treatment under Ar, air, 5%H2/N2 or NH3.The LiCoPO4 prepared after heating in Ar exhibited high initial discharge capacity of 147 mA h g-1 at0.1 C with capacity retention of 70% after 40 cycles. This is attributed to the enhanced electronic conductivity of LiCoPO4 due to the presence of Co2P after firing under Ar. In addition, Li4Ti5O12 synthesized via solid-state reaction with 2% Li excesses were found to have minimum TiO2 impurities, which delivered an initial capacity of 165 mA h g-1. TiN were coated onto Li4Ti5O12 anodes in lithium-ion batteries, which exhibited improved initial capacity of 174 mA h g-1. Finally, nanostructured TiN were prepared by a cross-linked sol-gel method with HDA or P123 as a surfactant, or evaporation induced self-assembly method with PEO-b-PS as a surfactant, and heated under NH3 at a variety of processing conditions. Mesoporous TiN with worm-like morphology and pore size of ~20 nm were obtained, and selected TiN samples have been used as host materials for sulfur cathodes in lithium-sulfur batteries.
University of Southampton
Zhang, Min
a7325ff1-529e-4010-9877-36b486325e6a
Zhang, Min
a7325ff1-529e-4010-9877-36b486325e6a
Hector, Andrew
f19a8f31-b37f-4474-b32a-b7cf05b9f0e5

Zhang, Min (2019) Applications of metal nitride nanostructures in stabilising high energy and high capacity battery systems. University Secretary, Doctoral Thesis, 419pp.

Record type: Thesis (Doctoral)

Abstract

Applications of metal nitride nanostructures in stabilising high energy and high capacity battery systems were investigated. Sol-gel synthesis routes using tetrakis(dimethylamido)titanium(IV) and a propylamine or ammonia cross linking agent, followed by thermal treatment under NH3 or H2+N2,were developed to produce TiN powders of small crystallite size (<10 nm). The TiN with good conductivity were coated on LiFePO4 cathodes in lithium-ion batteries, which exhibited significantly improved electrochemical performance with a discharge capacity of 159 mA h g-1 at 0.1 C, that is~93% of the theoretical capacity. A literature review of various synthetic routes such as solid-state reactions, hydrothermal/solvothermal synthesis and sol-gel process to produce LiCoPO4 was performed, and various strategies such as surface modification, ion doping, size reduction and morphology control to improve the electrochemical performance of LiCoPO4 were summarised. Olivine-structured LiCoPO4 was prepared via a facile solvothermal synthesis, using various ratios of water/diethylene glycol co-solvent, followed by thermal treatment under Ar, air, 5%H2/N2 or NH3.The LiCoPO4 prepared after heating in Ar exhibited high initial discharge capacity of 147 mA h g-1 at0.1 C with capacity retention of 70% after 40 cycles. This is attributed to the enhanced electronic conductivity of LiCoPO4 due to the presence of Co2P after firing under Ar. In addition, Li4Ti5O12 synthesized via solid-state reaction with 2% Li excesses were found to have minimum TiO2 impurities, which delivered an initial capacity of 165 mA h g-1. TiN were coated onto Li4Ti5O12 anodes in lithium-ion batteries, which exhibited improved initial capacity of 174 mA h g-1. Finally, nanostructured TiN were prepared by a cross-linked sol-gel method with HDA or P123 as a surfactant, or evaporation induced self-assembly method with PEO-b-PS as a surfactant, and heated under NH3 at a variety of processing conditions. Mesoporous TiN with worm-like morphology and pore size of ~20 nm were obtained, and selected TiN samples have been used as host materials for sulfur cathodes in lithium-sulfur batteries.

Text
Min Zhang - PhD Thesis - Electrochemistry - 20190429 - Version of Record
Available under License University of Southampton Thesis Licence.
Download (13MB)

More information

Published date: April 2019

Identifiers

Local EPrints ID: 433122
URI: http://eprints.soton.ac.uk/id/eprint/433122
PURE UUID: 29a63159-5814-4fab-bc29-c7ff9b4a896d
ORCID for Andrew Hector: ORCID iD orcid.org/0000-0002-9964-2163

Catalogue record

Date deposited: 08 Aug 2019 16:30
Last modified: 07 May 2021 04:01

Export record

Contributors

Author: Min Zhang
Thesis advisor: Andrew Hector ORCID iD

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×