Cu₂S@ N, S Dual‐Doped Carbon Matrix Hybrid as Superior Anode Materials for Lithium/Sodium ion Batteries

Abstract

Cu2S is considered as a promising electrode material for lithium‐ion and sodium‐ion batteries owing to its flat charge‐discharge plateau as well as the abundant reserves. However, serious capacity fading and formation of polysulfides during electrochemical process restrict its practical application. In this work, a new type of Cu2S@N, S dual‐doped carbon matrix (Cu2S@NSCm) hybrid is synthesized through a simple in‐situ polymerization process and subsequent carbonization process. Due to the N, S dual‐doped carbon matrix, which can buffer the volume change, restrain the dissolution of polysulfide and enhance the electron conductivity during electrochemical process, the hybrid demonstrates excellent electrochemical performance. The Cu2S@NSCm hybrid exhibits a reversible capacity of 560.1 mAh g−1 at a current density of 1000 mA g−1 after 550 cycles when used in lithium‐ion batteries, which is among the best performance for Cu2S based anode materials. Moreover, a capacity of 182.3 mAh g−1 is obtained after 50 cycles when used as an anode material in sodium ion batteries, which is much better than the pure Cu2S.

Bullet‐like Cu9S5 Hollow Particles Coated with Nitrogen‐Doped Carbon for Sodium‐Ion Batteries

“…The Cu 9 S 5 @NC electrode can deliver a reversible charge capacity of about 385 mAh g −1 with a high initial Coulombic efficiency of about 94 %. The reversible capacity is higher than that of the Cu 9 S 5 electrode (218 mAh g −1 , Figure S12) and most of the previously reported Cu x S‐based electrodes . The capacity of the Cu 9 S 5 @NC electrode shows some decay in the first few cycles but quickly stabilizes after 10 cycles.…”

“…For comparison, the capacity of the Cu 9 S 5 electrode drops rapidly with cycling (Figure d,e). The cycling performance of the bullet‐like Cu 9 S 5 @NC hollow particles is also superior to that of other reported Cu x S‐based electrodes . The carbon coating layer helps to maintain the bullet structure of Cu 9 S 5 as verified by FESEM observation after long‐term cycling (Figure S18).…”

“…In contrast, the specific capacity of the Cu 9 S 5 electrode fades rapidly with the increase of current density. The rate capability of the Cu 9 S 5 @NC electrodes is also superior to that of the bulk Cu 9 S 5 particles (Figures S15 and S16) and most of the Cu x S‐based electrodes …”

“…In contrast, the specific capacity of the Cu 9 S 5 electrode fades rapidly with the increase of current density.T he rate capability of the Cu 9 S 5 @NC electrodes is also superior to that of the bulk Cu 9 S 5 particles (Figures S15 and S16) and most of the Cu x S-based electrodes. [30,[39][40][41][42][44][45][46][47] Moreover,t he Cu 9 S 5 @NC electrode also exhibits excellent cycling stability.S pecifically,t he electrode exhibits stable cycling performance over 500 cycles at 0.3 Ag À1 (Figure 4d). At ah igher current density of 2Ag À1 ,even after 4000 cycles,acapacity retention of 79 %can still be achieved (Figure 4e), corresponding to an average capacity loss of only 0.0053 %per cycle.…”

ZnS Nanotubes/Carbon Cloth as a Reversible and High‐Capacity Anode Material for Lithium‐Ion Batteries

“…However, its capacity as low as 372 mAh g −1 set a barrier to its further development . Thus, a variety of materials have been analyzed in order to find a suitable alternative anode for lithium‐ion batteries . Among them, ZnS has been regarded as a very promising substitute to graphite as it possesses high theoretical capacity (962 mAh g −1 ) and electrochemical stability in organic electrolytes ,.…”