Heterostructure SnSe₂/ZnSe@PDA Nanobox for Stable and Highly Efficient Sodium‐Ion Storage

Abstract

Rationally designed electrode materials with high capacity, long cycle life, and low cost are indispensable for sodium‐ion batteries. Herein, a hierarchical nanobox consisting of a heterojunction bimetallic selenide yolk and polydopamine shell (denoted as SnSe2/ZnSe@PDA) is engineered and fabricated successfully. Owing to the charge redistribution and lattice distortion at the hetero‐phase boundaries, Na+ ions can be easily adsorbed and transferred swiftly, facilitating the reaction kinetics and promoting cycling behavior. By means of the hollow structure and elastic polymer shell, this approach can synergistically alleviate volume fluctuation and the aggregation of active nanomaterials during cycling. This material delivers a high reversible capacity of 616 mA h g‐1 at 1 A g‐1 over 1000 long‐term cycles, and superior rate capability, which provides more possibilities for the practical applications of energy storage in the future.

TiO2‐Based Heterostructures with Different Mechanism: A General Synergistic Effect toward High‐Performance Sodium Storage

“…[ 26–28 ] The redistribution of electron density of TiO 2 and SnS 2 can promote the transport of Na ions, and finally lead to the acceleration in reaction kinetics at the SnS 2 /TiO 2 heterointerface. [ 25,29 ] In addition, the S 2p peaks at 161.9 and 163.1 eV correspond to the S 2p 3/2 and S 2p 1/2 , respectively (Figure 3I). O 1s spectrum could be divided into three peaks at 529.7, 531.3, and 533.0 eV (Figure 3G), coming from the oxygen of the rutile lattice network, surficial OH groups, and adsorbed water molecules (H 2 O), respectively.…”

Fe7Se8 encapsulated in N-doped carbon nanofibers as a stable anode material for sodium ion batteries

“…All b values of Fe 7 Se 8 -NCFs are closed to 1, which suggests the main pseudocapacitive behavior in redox reactions. On the other hand, we calculated the ratio of pseudocapacitive contribution according to equation as following [32,33]:…”

Promoting Ge Alloying Reaction via Heterostructure Engineering for High Efficient and Ultra‐Stable Sodium‐Ion Storage

“…Figure 5e and Figure S14, Supporting Information, shows the GITT curves of Cu 3 Ge/Ge@N‐C and Cu 3 Ge/Ge. The apparent D Na+ can be calculated according to the following equation: [ 46 ] where τ is the current pulse time (s), m and M are the mass and molar mass of Ge, and V m is the molar volume of the active materials, A is the surface area of the electrode. Δ E s and Δ E τ are potential variations of quasi‐equilibrium potential and potential variation during a constant current pulse.…”

“…Figure 5e and Figure S14, Supporting Information, shows the GITT curves of Cu 3 Ge/Ge@N-C and Cu 3 Ge/Ge. The apparent D Na+ can be calculated according to the following equation: [46]…”