Rational Design of Yolk–Shell ZnCoSe@N‐Doped Dual Carbon Architectures as Long‐Life and High‐Rate Anodes for Half/Full Na‐Ion Batteries

Abstract

Transition‐metal selenides (TMSs) have emerged as prospective anode materials for sodium ion batteries (SIBs), owing to their considerable theoretical capacity and intrinsic high electronic conductivity. Whereas, TMSs still suffer from poor rate capability and inferior cycling stability induced by sluggish kinetics and severe volume changes during de/sodiation processes. Herein, a hierarchical composite consisting of a zinc‐cobalt bimetallic selenide yolk and nitrogen‐doped double carbon shell (denoted as ZnCoSe@NDC) is engineered and fabricated successfully. The architecture of the as‐fabricated material improves the Na‐ion storage performance via increasing the electron transfer kinetics, accommodating volume expansion, and mitigating the generation of by‐products. As expected, the ZnCoSe@NDC electrode delivers superior sodium storage performance with long cycling stability (344.5 mAh g−1 at 5.0 A g−1 over 2000 long‐term cycles) and high‐rate performance (319.2 mAh g−1 at 10.0 A g−1). Meanwhile, the NVP@C//ZnCoSe@NDC full SIB cells are constructed successfully, retaining 96.3% of its initial capacity at 0.5A g−1 after 200 loops. The outstanding electrochemical performance and the construction of hybrid SIBs will have far‐reaching influences on the development of the various rechargeable batteries.

Multifunctional Cr Substitution Modulates Electrochemical Activity of Mn1–xCrxO for High-Performance Lithium-Ion Battery Anodes

“…The calculated results (Figure e,g, and Figure S6) show that the Mn 0.94 Cr 0.06 O electrode (−8.85/–9.12 cm 2 s –1 ) has a larger log D value compared to the MnO electrode (−8.91/–9.29 cm 2 s –1 ) during the discharge/charging process, indicating that Cr substitution can promote and improve the lithium-ion diffusion kinetics and energy storage. As shown in Figure S7a, the electrochemical impedance spectrum (EIS) is accompanied by typical semicircles in the high-frequency region and straight lines in the low-frequency region, which are related to the charge transfer at the interface (Rct) and the diffusion of lithium-ions, respectively. , The observed and fitted results (Figure S7b) show that Cr substitution significantly reduces Rct, indicating that Cr substitution can enhance the kinetics of electron transfer between the electrode and electrolyte and thus stimulate the electrochemical activity of the electrode material.…”

“…As shown in Figure S7a, the electrochemical impedance spectrum (EIS) is accompanied by typical semicircles in the high-frequency region and straight lines in the low-frequency region, which are related to the charge transfer at the interface (Rct) and the diffusion of lithium-ions, respectively. 65,66 The observed and fitted results (Figure S7b) show that Cr substitution significantly reduces Rct, indicating that Cr substitution can enhance the kinetics of electron transfer between the electrode and electrolyte and thus stimulate the electrochemical activity of the electrode material.…”

“…To investigate the effect of Cr substitution on the kinetic characteristics of the electrode, the GITT was performed to calculate the lithium-ion diffusion coefficient based on the simplified equation. , …”

Regulation of the Electronic Properties of Graphene via Organic Molecular Intercalation

“…The peaks at 284.9 and 287.3 eV can be assigned to the chemical bonding of C–C and C–N, with sp 3 -hybridized carbon, respectively (Figure S4b). − The N 1s peak at 399.5 eV denotes quaternary N from TBA + (Figure S4c). The XPS survey spectrum of Gr/Ac suggests the existence of carbon and oxygen (Figure S4d).…”

Ultrafine ZnSe/CoSe nanodots encapsulated in core–shell MOF-derived hierarchically porous N-doped carbon nanotubes for superior lithium/sodium storage

“…ZnSe@CoSe@CN is among the best selenide-based anode materials for SIBs (Fig. 5e and Table S4) [37,39,[53][54][55][56][57][58][59].…”