TY - JOUR
T1 - Highlighting the importance of full-cell testing for high performance anode materials comprising Li alloying nanowires
AU - Geaney, Hugh
AU - Bree, Gerard
AU - Stokes, Killian
AU - McCarthy, Kieran
AU - Kennedy, Tadhg
AU - Ryan, Kevin M.
N1 - Publisher Copyright:
© 2019 The Electrochemical Society.
PY - 2019
Y1 - 2019
N2 - Herein, the electrochemical performance of directly grown Ge nanowire anodes in full-cell Li-ion configurations (using lithium cobalt oxide cathodes) are examined. The impacts of voltage window, anode/cathode balancing and anode preconditioning are assessed. The cells had a useable upper cutoff of 3.9 V, with a higher voltage cutoff of 4.2 V shown by SEM analysis to lead to Li plating on the anode surface. The rate performance of Ge NW anodes was shown to be boosted within full-cells compared to half-cells, meaning that existing studies may underestimate the rate performance of alloying mode anode materials if they are only based on half-cell investigations. The capacity retention of the full-cells is lower compared to equivalent half-cells due to progressive consumption of cyclable Li. This phenomenon is demonstrated using a parallel anode and cathode delithiation approach that could be extended to other full-cell systems. The findings stress the importance of testing promising anode materials within full-cell configurations, to identify specific capacity fade mechanisms that are not relevant to half-cells and aid the development of higher energy density storage systems.
AB - Herein, the electrochemical performance of directly grown Ge nanowire anodes in full-cell Li-ion configurations (using lithium cobalt oxide cathodes) are examined. The impacts of voltage window, anode/cathode balancing and anode preconditioning are assessed. The cells had a useable upper cutoff of 3.9 V, with a higher voltage cutoff of 4.2 V shown by SEM analysis to lead to Li plating on the anode surface. The rate performance of Ge NW anodes was shown to be boosted within full-cells compared to half-cells, meaning that existing studies may underestimate the rate performance of alloying mode anode materials if they are only based on half-cell investigations. The capacity retention of the full-cells is lower compared to equivalent half-cells due to progressive consumption of cyclable Li. This phenomenon is demonstrated using a parallel anode and cathode delithiation approach that could be extended to other full-cell systems. The findings stress the importance of testing promising anode materials within full-cell configurations, to identify specific capacity fade mechanisms that are not relevant to half-cells and aid the development of higher energy density storage systems.
UR - http://www.scopus.com/inward/record.url?scp=85073686577&partnerID=8YFLogxK
U2 - 10.1149/2.0291913jes
DO - 10.1149/2.0291913jes
M3 - Article
AN - SCOPUS:85073686577
SN - 0013-4651
VL - 166
SP - A2784-A2790
JO - Journal of the Electrochemical Society
JF - Journal of the Electrochemical Society
IS - 13
ER -