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Dr. Tadhg Kennedy

Biography

Tadhg studied Pharmaceutical and Industrial Chemistry at undergraduate level before obtaining his PhD in Chemistry in the University of Limerick. He is currently a lecturer in the Department of Chemical and Environmental Sciences where his teaching interests lie in physical, analytical and inorganic chemistry.

Tadhg's research involves the development of high-capacity electrode materials for energy storage devices. His primary focus is on the application of nanostructured semiconductor anodes for next-generation lithium-ion batteries. He has considerable experience in the development of low-cost synthetic methods for lithium-alloying electrodes based on Si and Ge and the enhancement of their cycling performance through morphology control and electrolyte optimisation. Tadhg is currently involved in a large scale collaborative project with the FP7 involving 17 EU partners known as the Greenlion project with the main objective being the manufacture of greener and cheaper lithium-ion batteries for electric vehicle applications.

Research Interests

There is an ever-growing demand for rechargeable batteries with reversible and efficient electrochemical energy storage and conversion. Lithium-ion batteries are by far the most popular on the market today and during the past three decades there has been great interest in developing active materials with improved electrochemical performance, particularly in alternatives to the graphite anode which has a relatively low maximum theoretical specific capacity of 372 mAh/g. Silicon and germanium based anodes are promising replacement candidates as they exhibit capacities that are multiples of graphite due to their ability to form lithium-rich alloys during charging. However, the formation of these high-capacity lithiated alloys, Li15Si4 (3579 mAh/g) and Li15Ge4 (1384 mAh/g), leads to considerable expansion of bulk Si and Ge electrodes (> 300%) which causes pulverisation of the material and loss of contact with the current collector, ultimately limiting the cycle life of Li-alloying anodes. By employing nanoscale materials this issue can be circumvented as the nano-dimensions can accommodate the large volume change without fracture, leading to a longer cycle life for the electrode.

My research involves the development of Si and Ge nanowire based electrodes as high-capacity anodes for next-generation Li-ion batteries. The unique morphology is well suited for lithium-ion battery applications as nanowires provide good electrical conductivity along their length, have a high interfacial area in contact with the electrolyte, have an optimal short diffusion distance for Li-ion transport, and can be grown directly from current collectors, eliminating the need for binders and conductive additives. These nanowire anodes have long cycle lives comparable to conventional graphitic anodes while delivering over three times the capacity over extended cycles. In particular in my research I look at:

·

Development of rapid synthetic methods for substrate grown nanowires

·

Identification of Li active catalyst materials for nanowire growth

·

Electrochemical characterisation of Si and Ge nanowire electrodes

·

Analysis of the effect of cycling on nanowire integrity and morphology

·

Electrolyte development and characterisation

Professional Activities

Award

  • 2015 - MSSI Best Postgraduate Web of Science Journal Publication in 2014
  • 2014 - Irish Research Council Government of Ireland ‘New Foundations' Award
  • 2010 - Bristol Myers Squibb Gold Medal
  • 2010 - Advanced Scholar Award

Publications

Book Chapters

2015

GREENLION Project: Advanced Manufacturing Processes for Low Cost Greener Li-Ion Batteries. In Electric Vehicle Batteries: Moving from Research towards Innovation
de Meatza, I.; Miguel, O.; Cendoya, I.; Kim, G.-T.; Löffler, N.; Laszczynski, N.; Passerini, S.; Schweizer, P. M.; Castiglione, F.; Mele, A.; Battista Appetecchi, G.; Moreno, M.; Brandon, M.; Kennedy, T.; Mullane, E.; Ryan, K. M.; Cantero, I.; Olive, M
(2015) GREENLION Project: Advanced Manufacturing Processes for Low Cost Greener Li-Ion Batteries. In Electric Vehicle Batteries: Moving from Research towards Innovation
In Electric Vehicle Batteries: Moving from Research towards Innovation; Switzerland : Springer

Peer Reviewed Journals

2020

Comparing nanoparticles for drug delivery: The effect of physiological dispersion media on nanoparticle properties
Ross A.M.;Kennedy T.;McNulty D.;Leahy C.I.;Walsh D.R.;Murray P.;Grabrucker A.M.;Mulvihill J.J.E.
(2020) Comparing nanoparticles for drug delivery: The effect of physiological dispersion media on nanoparticle properties
In Materials Science & Engineering C-Materials For Biological Applications;
DOI: 10.1016/j.msec.2020.110985
[ULIR]

2019

Highlighting the importance of full-cell testing for high performance anode materials comprising Li alloying nanowires
Geaney H.;Bree G.;Stokes K.;McCarthy K.;Kennedy T.;Ryan K.
(2019) Highlighting the importance of full-cell testing for high performance anode materials comprising Li alloying nanowires
In Journal Of The Electrochemical Society; pp. A2784-A2790
DOI: 10.1149/2.0291913jes
[ULIR]

2019

Enhancing the performance of germanium nanowire anodes for Li-ion batteries by direct growth on textured copper
Geaney, Hugh and Bree, Gerard and Stokes, Killian and Collins, Gearoid A and Aminu, Ibrahim Saana and Kennedy, Tadhg and Ryan, Kevin M
(2019) Enhancing the performance of germanium nanowire anodes for Li-ion batteries by direct growth on textured copper
In Chemical Communications; pp. 7780-7783
[ULIR]

2019

Tunable Core--Shell Nanowire Active Material for High Capacity Li-Ion Battery Anodes Comprised of PECVD Deposited aSi on Directly Grown Ge Nanowires
Stokes, Killian and Boonen, Wil and Geaney, Hugh and Kennedy, Tadhg and Borsa, Dana and Ryan, Kevin M
(2019) Tunable Core--Shell Nanowire Active Material for High Capacity Li-Ion Battery Anodes Comprised of PECVD Deposited aSi on Directly Grown Ge Nanowires
In ACS applied materials & interfaces; pp. 19372-19380

2019

Tunable Core-Shell Nanowire Active Material for High Capacity Li-Ion Battery Anodes Comprised of PECVD Deposited aSi on Directly Grown Ge Nanowires
Stokes K.;Boonen W.;Geaney H.;Kennedy T.;Borsa D.;Ryan K.
(2019) Tunable Core-Shell Nanowire Active Material for High Capacity Li-Ion Battery Anodes Comprised of PECVD Deposited aSi on Directly Grown Ge Nanowires
In ACS Applied Materials & Interfaces; pp. 19372-19380
DOI: 10.1021/acsami.9b03931

2019

Enhancing the performance of germanium nanowire anodes for Li-ion batteries by direct growth on textured copper
Geaney H.;Bree G.;Stokes K.;Collins G.;Aminu I.;Kennedy T.;Ryan K.
(2019) Enhancing the performance of germanium nanowire anodes for Li-ion batteries by direct growth on textured copper
In Chemical Communications; pp. 7780-7783
DOI: 10.1039/c9cc03579f

2017

Understanding the influence of electrolyte additives on the electrochemical performance and morphology evolution of silicon nanowire based lithium-ion battery anodes
Kennedy, T,Brandon, M,Laffir, F,Ryan, KM
(2017) Understanding the influence of electrolyte additives on the electrochemical performance and morphology evolution of silicon nanowire based lithium-ion battery anodes
In Journal Of Power Sources; pp. 601-610
DOI: 10.1016/j.jpowsour.2017.05.093

2017

Behavior of Germanium and Silicon Nanowire Anodes with Ionic Liquid Electrolytes
Kim, GT,Kennedy, T,Brandon, M,Geaney, H,Ryan, KM,Passerini, S,Appetecchi, GB
(2017) Behavior of Germanium and Silicon Nanowire Anodes with Ionic Liquid Electrolytes
In Acs Nano; pp. 5933-5943
DOI: 10.1021/acsnano.7b01705

2017

Solution synthesis of lead seeded germanium nanowires and branched nanowire networks and their application as Li-ion battery anodes
Flynn, G,Palaniappan, K,Sheehan, M,Kennedy, T,Ryan, KM
(2017) Solution synthesis of lead seeded germanium nanowires and branched nanowire networks and their application as Li-ion battery anodes
In Nanotechnology;
DOI: 10.1088/1361-6528/aa72c7
[ULIR]

2017

Direct Synthesis of Alloyed Si1--x Ge x Nanowires for Performance-Tunable Lithium Ion Battery Anodes
Stokes, Killian and Geaney, Hugh and Flynn, Grace and Sheehan, Martin and Kennedy, Tadhg and Ryan, Kevin M
(2017) Direct Synthesis of Alloyed Si1--x Ge x Nanowires for Performance-Tunable Lithium Ion Battery Anodes
In ACS nano; pp. 10088-10096

2017

Behavior of germanium and silicon nanowire anodes with ionic liquid electrolytes
Kim, Guk-Tae and Kennedy, Tadhg and Brandon, Michael and Geaney, Hugh and Ryan, Kevin M and Passerini, Stefano and Appetecchi, Giovanni B
(2017) Behavior of germanium and silicon nanowire anodes with ionic liquid electrolytes
In ACS nano; pp. 5933-5943

2017

Direct Synthesis of Alloyed Si1-xGex Nanowires for Performance-Tunable Lithium Ion Battery Anodes
Stokes, K,Geaney, H,Flynn, G,Sheehan, M,Kennedy, T,Ryan, KM
(2017) Direct Synthesis of Alloyed Si1-xGex Nanowires for Performance-Tunable Lithium Ion Battery Anodes
In Acs Nano; pp. 10088-10096
DOI: 10.1021/acsnano.7b04523

2016

Advances in the Application of Silicon and Germanium Nanowires for High-Performance Lithium-Ion Batteries
Tadhg Kennedy, Michael Brandon, Kevin M. Ryan
(2016) Advances in the Application of Silicon and Germanium Nanowires for High-Performance Lithium-Ion Batteries
In Advanced Materials;

2015

Nanowire Heterostructures Comprising Germanium Stems and Silicon Branches as High-Capacity Li-Ion Anodes with Tunable Rate Capability
Kennedy, T,Bezuidenhout, M,Palaniappan, K,Stokes, K,Brandon, M,Ryan, KM
(2015) Nanowire Heterostructures Comprising Germanium Stems and Silicon Branches as High-Capacity Li-Ion Anodes with Tunable Rate Capability
In Acs Nano; pp. 7456-7465
DOI: 10.1021/acsnano.5b02528

2015

High density and patternable growth of silicon, germanium and alloyed SiGe nanowires by a rapid anneal protocol
Bezuidenhout, M,Kennedy, T,Belochapkine, S,Guo, Y,Mullane, E,Kiely, PA,Ryan, KM
(2015) High density and patternable growth of silicon, germanium and alloyed SiGe nanowires by a rapid anneal protocol
In Journal Of Materials Chemistry C; pp. 7455-7462
DOI: 10.1039/c5tc01389e

2014

A rapid, solvent-free protocol for the synthesis of germanium nanowire lithium-ion anodes with a long cycle life and high rate capability
Mullane, Emma and Kennedy, Tadhg and Geaney, Hugh and Ryan, Kevin M
(2014) A rapid, solvent-free protocol for the synthesis of germanium nanowire lithium-ion anodes with a long cycle life and high rate capability
In ACS applied materials & interfaces; pp. 18800-18807

2014

High-performance germanium nanowire-based lithium-ion battery anodes extending over 1000 cycles through in situ formation of a continuous porous network
Kennedy, Tadhg and Mullane, Emma and Geaney, Hugh and Osiak, Michal and O’Dwyer, Colm and Ryan, Kevin M
(2014) High-performance germanium nanowire-based lithium-ion battery anodes extending over 1000 cycles through in situ formation of a continuous porous network
In Nano letters; pp. 716-723

2014

High-Performance Germanium Nanowire-Based Lithium-Ion Battery Anodes Extending over 1000 Cycles Through in Situ Formation of a Continuous Porous Network
Kennedy, T,Mullane, E,Geaney, H,Osiak, M,O'Dwyer, C,Ryan, KM
(2014) High-Performance Germanium Nanowire-Based Lithium-Ion Battery Anodes Extending over 1000 Cycles Through in Situ Formation of a Continuous Porous Network
In Nano Letters; pp. 716-723
DOI: 10.1021/nl403979s
[ULIR]

2014

A Rapid, Solvent-Free Protocol for the Synthesis of Germanium Nanowire Lithium-Ion Anodes with a Long Cycle Life and High Rate Capability
Mullane, E,Kennedy, T,Geaney, H,Ryan, KM
(2014) A Rapid, Solvent-Free Protocol for the Synthesis of Germanium Nanowire Lithium-Ion Anodes with a Long Cycle Life and High Rate Capability
In ACS Applied Materials & Interfaces; pp. 18800-18807
DOI: 10.1021/am5045168

2013

Synthesis of tin catalyzed silicon and germanium nanowires in a solvent--vapor system and optimization of the seed/nanowire interface for dual lithium cycling
Mullane, Emma and Kennedy, Tadhg and Geaney, Hugh and Dickinson, Calum and Ryan, Kevin M
(2013) Synthesis of tin catalyzed silicon and germanium nanowires in a solvent--vapor system and optimization of the seed/nanowire interface for dual lithium cycling
In Chemistry of Materials; pp. 1816-1822

2013

Synthesis of Tin Catalyzed Silicon and Germanium Nanowires in a Solvent-Vapor System and Optimization of the Seed/Nanowire Interface for Dual Lithium Cycling
Mullane, E,Kennedy, T,Geaney, H,Dickinson, C,Ryan, KM
(2013) Synthesis of Tin Catalyzed Silicon and Germanium Nanowires in a Solvent-Vapor System and Optimization of the Seed/Nanowire Interface for Dual Lithium Cycling
In Chemistry Of Materials; pp. 1816-1822
DOI: 10.1021/cm400367v

2013

Epitaxial growth of visible to infra-red transparent conducting In2O3 nanodot dispersions and reversible charge storage as a Li-ion battery anode
Osiak, M,Khunsin, W,Armstrong, E,Kennedy, T,Torres, CMS,Ryan, KM,O'Dwyer, C
(2013) Epitaxial growth of visible to infra-red transparent conducting In2O3 nanodot dispersions and reversible charge storage as a Li-ion battery anode
In Nanotechnology;
DOI: 10.1088/0957-4484/24/6/065401
[ULIR]

2013

Core-Shell Tin Oxide, Indium Oxide, and Indium Tin Oxide Nanoparticles on Silicon with Tunable Dispersion: Electrochemical and Structural Characteristics as a Hybrid Li-Ion Battery Anode
Osiak, MJ,Armstrong, E,Kennedy, T,Torres, CMS,Ryan, KM,O'Dwyer, C
(2013) Core-Shell Tin Oxide, Indium Oxide, and Indium Tin Oxide Nanoparticles on Silicon with Tunable Dispersion: Electrochemical and Structural Characteristics as a Hybrid Li-Ion Battery Anode
In ACS Applied Materials & Interfaces; pp. 8195-8202
DOI: 10.1021/am4023169

2012

High Density Growth of Indium seeded Silicon Nanowires in the Vapor phase of a High Boiling Point Solvent
Geaney, Hugh and Kennedy, Tadhg and Dickinson, Calum and Mullane, Emma and Singh, Ajay and Laffir, Fathima and Ryan, Kevin M
(2012) High Density Growth of Indium seeded Silicon Nanowires in the Vapor phase of a High Boiling Point Solvent
In Chemistry of Materials; pp. 2204-2210

2012

High Density Growth of Indium seeded Silicon Nanowires in the Vapor phase of a High Boiling Point Solvent
Geaney, H,Kennedy, T,Dickinson, C,Mullane, E,Singh, A,Laffir, F,Ryan, KM
(2012) High Density Growth of Indium seeded Silicon Nanowires in the Vapor phase of a High Boiling Point Solvent
In Chemistry Of Materials; pp. 2204-2210
DOI: 10.1021/cm301023j

Conference Publications

2014

Meeting Abstracts
Kennedy, Tadhg and Mullane, Emma and Geaney, Hugh and Osiak, Michal and O'Dwyer, Colm and Ryan, Kevin M
(2014) Meeting Abstracts
pp. 446-446

2013

ECS Transactions
Osiak M.;Khunsin W.;Armstrong E.;Kennedy T.;Sotomayor Torres C.;Ryan K.;O'Dwyer C.
(2013) ECS Transactions
In Ecs Transactions; pp. 53-61
DOI: 10.1149/05306.0053ecst

2013

ECS Transactions
Osiak M.;Armstrong E.;Kennedy T.;Torres C.;Ryan K.;O'Dwyer C.
(2013) ECS Transactions
In Ecs Transactions; pp. 1-10
DOI: 10.1149/05310.0001ecst