posted on 2021-07-16, 22:13authored byYang Yang, Wenbin Fu, Crystal Bell, Dong-Chan Lee, Matthew Drexler, Yanna Nuli, Zi-Feng Ma, Alexandre Magasinski, Gleb Yushin, Faisal M. Alamgir
Iron
phosphide with high specific capacity has emerged as an appealing
candidate for next-generation lithium-ion battery anodes. However,
iron phosphide could undergo conversion reactions and generally suffer
from a rapid capacity degradation upon cycling due to its structure
pulverization. Chemomechanical breakdown of iron phosphide due to
its rigidity has been a challenge to fully realizing its electrochemical
performance. To address this challenge, we report here on an enticing
opportunity: a flexible, free-standing iron phosphide anode with Fe2P nanoparticles confined in carbon nanofibers may overcome
existing challenges. For the synthesis, we introduce a facile electrospinning
strategy that enables in situ formation of Fe2P within
a carbon matrix. Such a carbon matrix can effectively minimize the
structure change of Fe2P particles and protect them from
pulverization, allowing the electrodes to retain a free-standing structure
after long-term cycling. The produced electrodes showed excellent
electrochemical performance in lithium-ion half and full cells, as
well as in flexible pouch cells. These results demonstrate the successful
development of iron phosphide materials toward high capacity, light
weight, and flexible energy storage.