nl7b03290_si_001.pdf (582.1 kB)
Reduced Graphene Oxide/LiI Composite Lithium Ion Battery Cathodes
journal contribution
posted on 2017-10-20, 18:35 authored by Sanghyeon Kim, Sung-Kon Kim, Pengcheng Sun, Nuri Oh, Paul V. BraunLi-iodine chemistry is of interest
for electrochemical energy storage
because it has been shown to provide both high power and high energy
density. However, Li-iodine batteries are typically formed using Li
metal and elemental iodine, which presents safety and fabrication
challenges (e.g., the high vapor pressure of iodine). These disadvantages
could be circumvented by using LiI as a starting cathode. Here, we
present fabrication of a reduced graphene oxide (rGO)/LiI composite
cathode, enabling for the first time the use of LiI as the Li-ion
battery cathode. LiI was coated on rGO by infiltration of an ethanolic
solution of LiI into a compressed rGO aerogel followed by drying.
The free-standing rGO/LiI electrodes show stable long-term cycling
and good rate performance with high specific capacity (200 mAh g–1 at 0.5 C after 100 cycles) and small hysteresis (0.056
V at 1 C). Shuttling was suppressed significantly. We speculate the
improved electrochemical performance is due to strong interactions
between the active materials and rGO, and the reduced ion and electron
transport distances provided by the three-dimensional structured cathode.