Geaney Research Group

Materials for Energy Storage

Recent Publication Highlights

Materials Today Energy 2022
J. Mater. Chem. A, 2021
Small 2021, 2102333
J. Mater. Chem. A, 2021
ACS Appl. Energy Mater. 2021, 4, 2, 1793–1804
Nanoscale, 2020,12, 22307-22316
Nano Lett. 2019, 19, 12, 8829–8835
ChemSusChem 2019, 12,4516 –4521
Chem. Commun., 2019,55, 7780-7783
J. Electrochem. Soc. 2019 166 A2784

Si NW growth on flexible carbon cloth allowed for higher areal capacity anodes compared to NWs grown on stainless steel. The high density Si NWs, coupled with contribution from the electrochemically active current collector, increased the areal capacity  >2mAh/cm2.

Na-ion battery investigation of  Si,SixGe1-x and Ge NWs. We examine the roles of amorphization & elemental compositions in determining Na alloying reversibility. It is shown that amorphization unlocks cycling ability, with Si0.5Ge0.5 NWs having the best capacity retention.

Li-ion battery anodes formed using copper silicide nanowires as high surface area hosts for Si NW growth. The complex branched nanowires and high density growth allowed for increased areal capacities, towards practical devices.

Review on low temperature operation of Li-ion batteries, with particular focus on anode related mechanistic issues. Includes recent material advances and an examination of future opportunities to develop better performing, low temperature batteries.

Examination of the impact of electrolyte composition on high and low temperature performance of Ge/LCO full cells. Benchmarking vs graphite containing full-cells shows significant performance enhancement. Mechanistic insight into low temperature evolution of the Ge anodes was also provided. 
Examination of the performance of colloidal WSe2 nanocrystals as anodes for lithium-ion batteries. Demonstrating the role of crystal phase and morphology in determining performance. Collaboration with UGhent
The study examines Cu15Si4 nanowires as a conductive scaffold/host for amorphous Si active material. The anode architecture allows for long term cycling stability by accommodating structural changes in the active Si.
Report examining the use of lignin derived carbon nanofibers as Li-ion battery anodes. The role of the biopolymer used in determining porosity and Li-ion storage capacity was details. Collaboration with Dr Maurice Collins.
Using a textured Cu foil for direct growth of Ge nanowires leads to significant performance enhancement compared to planar stainless steel current collectors. The areal capacity and cycling stability are dramatically enhanced and linked to increased stability of the active material during cycling.
Full cell testing of Ge nanowire anodes shows the impact of cell preconditioning, voltage windows and cathode capacity excess. The findings also demonstrate that half-cells may underestimate the rate performance of promising anode materials.

Funding for this research comes from Science Foundation Ireland under a Starting Investigator Research Grant (SIRG).