Overcoming the Challenges of Freestanding Tin Oxide‐Based Composite Anodes to Achieve High Capacity and Increased Cycling Stability

Autor: Martin Finsterbusch, Florian Zoller, Markus Döblinger, Hannah Illner, Dina Fattakhova-Rohlfing, Thomas Bein, Zdene Combining Breve K Sofer, Daniel Böhm, Sebastian Häringer
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Advanced functional materials 31(43), 2106373-(2021). doi:10.1002/adfm.202106373
Popis: Freestanding electrodes are a promising way to increase the energy density of the batteries by decreasing the overall amount of electrochemically inactive materials. Freestanding antimony doped tin oxide (ATO)-based hybrid materials have not been reported so far, although this material has demonstrated excellent performance in conventionally designed electrodes. Two different strategies, namely electrospinning and freeze-casting, are explored for the fabrication of ATO-based hybrid materials. It is shown that the electrospinning of ATO/carbon based electrodes from polyvinyl pyrrolidone polymer (PVP) solutions was not successful, as the resulting electrode material suffers from rapid degradation. However, freestanding reduced graphene oxide (rGO) containing ATO/C/rGO nanocomposites prepared via a freeze-casting route demonstrates an impressive rate and cycling performance reaching 697 mAh g−¹ at a high current density of 4 A g−¹, which is 40 times higher as compared to SnO₂/rGO and also exceeds the freestanding SnO₂-based composites reported so far. Antimony doping of the nanosized tin oxide phase and carbon coating are thereby shown to be essential factors for appealing electrochemical performance. Finally, the freestanding ATO/C/rGO anodes are combined with freestanding LiFe₀.₂Mn₀.₈PO₄/rGO cathodes to obtain a full freestanding cell operating without metal current collector foils showing nonetheless an excellent cycling stability.
Databáze: OpenAIRE