Core–Shell Co, Zn Bimetallic Selenide Embedded Nitrogen-Doped Carbon Polyhedral Frameworks Assist in Sodium-Ion Battery Ultralong Cycle

Abstract

Sodium-ion batteries (SIBs) have become the best alternative to lithium-ion batteries. However, it is difficult to meet the efficiency of SIBs using graphite. Transition-metal selenides are expected to be ideal anode materials for SIBs, but some problems still need to be solved, such as poor conductivity and volume expansion. Here, we successfully synthesized a core−shell structure ZnSe@CoSe 2 /NC composite using ZIF-8@ZIF-67 as a precursor. The in situ decorated ZnSe and CoSe 2 nanoparticles on the NC polyhedral framework provide a rich active site for the entire electrode. In addition, the NC can simultaneously increase the conductivity and alleviate the volume effect generated during the cycling process. The ZnSe@CoSe 2 /NC composites exhibit excellent electrochemical performance when used in SIB anode materials. When the current density is 0.1 A g −1 , the reversible capacity is 499.1 mA h g −1 after 100 cycles. When the current density is increased to 1.0 A g −1 , a reversible capacity of 273.5 mA h g −1 after 4000 cycles is delivered. In addition, the ZnSe@CoSe 2 /NC composite also exhibits superior rate performance. The sodium reaction kinetics of the ZnSe@CoSe 2 /NC composite was analyzed to explain its outstanding electrochemical performance. These results reveal the enormous potential of ZnSe@CoSe 2 /NC composites in building efficient SIBs.

MOF-derived multifunctional filler reinforced polymer electrolyte for solid-state lithium batteries

“…Lithium ion batteries (LIBs) have been widely used as power sources in mobile electronic equipment and large energy storage systems [1][2][3][4][5]. However, the electrolytes used in current LIBs are mainly combustible organic compounds, so there are serious safety risks.…”

“…Because of its diverse structure and strong design, MOF is an excellent candidate for building high performance SSEs [17,18]. The role of MOF in SSEs can be summarized as follows [14,19,20]: (1) The high specific surface area of MOF may be beneficial to full contact with other components. Its controllable surface polarity can adjust the interaction between Lewis acid and base in the system.…”

Hierarchical Co3Se4 Nanoparticles Encapsulated in a Nitrogen‐Doped Carbon Framework Intertwined with Carbon Nanotubes as Anode of Li‐Ion Batteries

“…[40] The peaks at 1359 cm À1 (D band) and 1590 cm À1 (G band) are ascribed to structural defects and sp 2 -bonded pairs. [41] The intensity ratio (I d /I g ) of N-Co 3 Se 4 @C-CNTs is 0.94, which is somewhat higher than that of N-Co@C-CNTs (0.91), implying increased carbon defects in N-Co 3 Se 4 @C-CNTs after the selenization process. TGA was performed in air to determine the mass ratio of carbon in N-Co 3 Se 4 @C-CNTs (Figure 3c).…”

Enhanced Sodium Storage Performance of Co7Se8 Enabled Through In Situ Formation of a Nanoporous Architecture

“…[21] The Co 7 Se 8 @C anode material is highlighted here due to its exclusive electronic configuration, great unsaturated atoms, and unique reaction mechanism. [22,23] However, such anode material still suffer from sluggish ion diffusion kinetics and severe volume variations during the repeat de/insertion process, which may result in poor cyclability and detachment of active materials from the current collector. [24,25] Combining the selenide anode materials with carbon materials is an effective way of buffering the volume expansions during the insertion procedure.…”

“…On the other hand, the transition metal selenide composites are prone to form hollow structures during the calcination procedure due to the Kirkendall effect, which is beneficial to the charge/mass transfer during the de/insertion process and the penetration of the electrolytes [21] . The Co 7 Se 8 @C anode material is highlighted here due to its exclusive electronic configuration, great unsaturated atoms, and unique reaction mechanism [22,23] . However, such anode material still suffer from sluggish ion diffusion kinetics and severe volume variations during the repeat de/insertion process, which may result in poor cyclability and detachment of active materials from the current collector [24,25] .…”