Urchin‐Like CoSe₂ as a High‐Performance Anode Material for Sodium‐Ion Batteries

Abstract

Urchin‐like CoSe2 assembled by nanorods has been synthesized via simple solvothermal route and has been first applied as an anode material for sodium‐ion batteries (SIBs) with ether‐based electrolytes. The CoSe2 delivers excellent sodiation and desodiation properties when using 1 m NaCF3SO3 in diethyleneglycol dimethylether as an electrolyte and cycling between 0.5 and 3.0 V. A high discharge capacity of 0.410 Ah g−1 is obtained at 1 A g−1 after 1800 cycles, corresponding to a capacity retention of 98.6% calculated from the 30th cycle. Even at an ultrahigh rate of 50 A g−1, the capacity still maintains 0.097 Ah g−1. The reaction mechanism of the as‐prepared CoSe2 is also investigated. The results demonstrate that at discharged 1.56 V, insertion reaction occurs, while two conversion reactions take place at the second and third plateaus around 0.98 and 0.65 V. During the charge process, Co first reacts with Na2Se to form NaxCoSe2 and then turns back to CoSe2. In addition to Na/CoSe2 half cells, Na3V2(PO4)3/CoSe2 full cell with excessive amount of Na3V2(PO4)3 has been studied. The full cell exhibits a reversible capacity of 0.380 Ah g−1. This work definitely enriches the possibilities for anode materials for SIBs with high performance.

Bifunctional Conducting Polymer Coated CoP Core–Shell Nanowires on Carbon Paper as a Free‐Standing Anode for Sodium Ion Batteries

“…The smaller depressed semicircle at high frequency for CoP@PPy NWs/CP indicates the smaller charge transfer resistance (R ct ) of CoP@PPy NWs/CP compared to CoP NWs/CP. [1,18,35] The TEM images of CoP@PPy NWs/CP electrode in the first, tenth, and 100th discharge states are shown in Figure S13 of the Supporting Information. The Nyquist plots of the CoP@PPy NWs/CP electrode after 1, 50, and 100 cycles are shown in Figure 5b, for which an equivalent circuit different from Figure 5a was employed.…”

Advanced Phosphorus‐Based Materials for Lithium/Sodium‐Ion Batteries: Recent Developments and Future Perspectives

“…According to the 8th Lithium Supply and Markets Conference in 2016, the availability of lithium supply in the near term remains less of a certainty, and with excitement around LIB-powered electric vehicles booming, prices will continue to track upward. [20][21][22][23] As a consequence, the electrode materials with high capacity, long lifespan and low cost, which play pivotal roles for energy storage markets, have been ultimately exploited for both LIBs and SIBs. [15][16][17][18][19] In spite of many breakthroughs that have been achieved, the development of SIBs is relatively slow and immature in comparison to LIBs mainly because of the larger radius of Na + (1.09 Å vs 0.76 Å of Li + ).…”

Urchinlike ZnS Microspheres Decorated with Nitrogen‐Doped Carbon: A Superior Anode Material for Lithium and Sodium Storage

“…Chen et al [12] fabricated urchinlike CoSe 2 by af acile solvothermal process, andt he reversible sodium-storage capacity of CoSe 2 is 410 mAh g À1 after 1800 cycles at 1000 mA g À1 .F ue tal. Chen et al [12] fabricated urchinlike CoSe 2 by af acile solvothermal process, andt he reversible sodium-storage capacity of CoSe 2 is 410 mAh g À1 after 1800 cycles at 1000 mA g À1 .F ue tal.…”