TY - JOUR
T1 - On the use of gas diffusion layers as current collectors in Li-O2 battery cathodes
AU - Geaney, Hugh
AU - O'Connell, John
AU - Holmes, Justin D.
AU - O'Dwyer, Colm
N1 - Publisher Copyright:
© 2014 The Electrochemical Society.
PY - 2014
Y1 - 2014
N2 - We investigate the impact of using a carbon based gas diffusion layer (GDL) as the current collector for Li-O2 batteries. It is shown that the GDL actively participates in ORR during discharge conditions and, if its mass is not accounted for, can lead to inflated discharge capacity figures compared to inert cathode supports. SEM and XRD analyses show that Li2O2 discharge products form on cathodes composed of as-received GDL in a similar manner to that observed for carbon on stainless steel (SS) current collectors (at applied currents of 100 μA cm-2 or less). The relative activity of the GDL, carbon on GDL and carbon-on-stainless steel current collectors from voltammetric measurements confirmed ORR and OER processes to be similar at all carbon-based surfaces. When heated above 300°C, degradation of the binder in the GDL and associated loss of carbon from the substrate surface leads to reduced discharge times compared to the pristine GDL substrates. The data highlight the importance of the contribution to ORR/OER in carbon-based active current collector substrates when determining gravimetric capacities of Li-O2 batteries.
AB - We investigate the impact of using a carbon based gas diffusion layer (GDL) as the current collector for Li-O2 batteries. It is shown that the GDL actively participates in ORR during discharge conditions and, if its mass is not accounted for, can lead to inflated discharge capacity figures compared to inert cathode supports. SEM and XRD analyses show that Li2O2 discharge products form on cathodes composed of as-received GDL in a similar manner to that observed for carbon on stainless steel (SS) current collectors (at applied currents of 100 μA cm-2 or less). The relative activity of the GDL, carbon on GDL and carbon-on-stainless steel current collectors from voltammetric measurements confirmed ORR and OER processes to be similar at all carbon-based surfaces. When heated above 300°C, degradation of the binder in the GDL and associated loss of carbon from the substrate surface leads to reduced discharge times compared to the pristine GDL substrates. The data highlight the importance of the contribution to ORR/OER in carbon-based active current collector substrates when determining gravimetric capacities of Li-O2 batteries.
UR - http://www.scopus.com/inward/record.url?scp=84923658527&partnerID=8YFLogxK
U2 - 10.1149/2.0021414jes
DO - 10.1149/2.0021414jes
M3 - Article
AN - SCOPUS:84923658527
SN - 0013-4651
VL - 161
SP - A1964-A1968
JO - Journal of the Electrochemical Society
JF - Journal of the Electrochemical Society
IS - 14
ER -