Abstract
As large-scale energy storage systems, rechargeable sodium-ion batteries (SIBs) are promising to replace the lithium-ion batteries. Among transition-metal dichalcogenides, which exhibit high theoretical capacities and specific two-dimensional layered structures, tungsten diselenide (WSe2) is an efficient anode material for SIBs owing to the good energetics and large lattice parameter. In this study, well-crystallized WSe2 nanosheets uniformly assembled on a porous carbon cloth (WSe2@PCC) were fabricated by an underwater electrical explosion of a tungsten wire, dip coating, and complete selenization from WO3 to WSe2. To further improve the cycling performance of the WSe2@PCC electrode, a carbon coating was carried out by simply adding sucrose into a WO3 ink before dip coating. The carbon-coated WSe2@PCC (C@WSe2@PCC) electrode exhibited outstanding electrochemical performances as a flexible and binder-free anode for SIBs due to enhanced electrical conductivity and mitigation of volume expansion of WSe2 during repeated sodiation/desodiation. Benefiting from unique structural merits and efficient carbon coating, C@WSe2@PCC can deliver large reversible areal capacity of 1.37 and 1.05 mA h cm−2 at the 1st and 150th cycles, respectively, with excellent capacity retention and Coulombic efficiency even at a high current density of 0.75 mA cm−2.
Original language | English |
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Article number | 154348 |
Journal | Journal of Alloys and Compounds |
Volume | 827 |
DOIs | |
Publication status | Published - 2020 Jun 25 |
Keywords
- Carbon coating
- Dip coating
- Electrical explosion of wire
- Porous carbon cloth
- Sodium-ion battery
- Tungsten diselenide
ASJC Scopus subject areas
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry