3D Ordered Porous Hybrid of ZnSe/N‐doped Carbon with Anomalously High Na⁺ Mobility and Ultrathin Solid Electrolyte Interphase for Sodium‐Ion Batteries

Abstract

Transition metal selenides have been widely used in alkali metal ion batteries owing to their high specific capacities and low cost. However, their reaction kinetics and structural stability are usually poor during cycling, along with ambiguous differences in Li/Na/K-storage behaviors. Herein, it is revealed that ZnSe possesses better Na + -diffusion kinetics (including lower diffusion barrier, smaller activation energy, and higher diffusion coefficients) in comparison with Li + and K + , as evidenced by theoretical calculations and electrochemical studies. The architectural designs of ZnSe-based anode, including nitrogen-doped carbon (N,C) and 3D ordered hierarchical pores (3DOHP) to form a 3DOHP ZnSe@N,C hybrid combined with regulating solid electrolyte interphase (SEI), significantly enhance Na + reaction kinetics and accommodate volume changes. The resulting 3DOHP ZnSe@N,C electrodes exhibit outstanding rate capability and good cycling stability (241.6 mAh g −1 in sodium-ion batteries (SIBs) at 10 A g −1 after 800 cycles), originating from improved electrical conductivity and shortened ion diffusion paths, accompanied by ultrathin and stable SEI with less Na 2 CO 3 /NaF in organic components and boosted Na 2 Se adsorption as sodiation. Moreover, the Na-storage mechanism in 3DOHP ZnSe@N,C hybrid is further revealed by in situ studies. Accordingly, this study provides a new perspective for designing high-performance electrode materials for SIBs.

Manipulating the Phase Compositions of Na3(VO1–xPO4)2F1+2x (0 ≤ x ≤ 1) and Their Synergistic Effects with Reduced Graphene Oxide toward High-Rate Sodium-Ion Batteries

“…79,80 The area ratio of the G and D1 bands (denoted as I G /I D ) of NVPF@rGO-600 °C was around 0.62 and higher than that of NVOPF@rGO-500 °C (0.50), which indicated less extrinsic defects of graphene and a higher graphitization degree of the rGO framework with a higher calcination temperature for the NVPF@rGO-600 °C sample. 81 The Raman results were consistent with the detected broad diffractions in the XRD patterns of NVPF@rGO-600 °C and NVOPF@rGO-500 °C samples. The highly graphitized rGO framework has a great impact on the overall electrical conductivity of NVPF@rGO-600 °C and NVOPF@rGO-500 °C samples, thus affecting their corresponding high-rate electrochemical performances, respectively.…”

“…The peak at 968.6 cm –1 corresponded to the VO stretching vibration, and the band at 500–600 cm –1 can be assigned to the coupling with V–O and P–O bend modes. − Two broad bands at 1596 and 1341 cm –1 , corresponding to the E 2g phonon of sp 2 -bonded carbon atoms in the graphitic layer (G-band) and the breathing mode of κ-point phonons with A 1g symmetry in the disordered carbon or defective graphitic structures (D-band, D1), , respectively, were shown in the NVPF@rGO-600 °C and NVOPF@rGO-500 °C samples. As shown in Figure b–c, the two peaks were fitted with four bands of D1, D3, D4, and G. The D3 peak represented the fragments or functional groups in the amorphous phase, which may change the C–C and CC stretching vibrations in the polyene-like structure (D4). , The area ratio of the G and D1 bands (denoted as I G / I D ) of NVPF@rGO-600 °C was around 0.62 and higher than that of NVOPF@rGO-500 °C (0.50), which indicated less extrinsic defects of graphene and a higher graphitization degree of the rGO framework with a higher calcination temperature for the NVPF@rGO-600 °C sample . The Raman results were consistent with the detected broad diffractions in the XRD patterns of NVPF@rGO-600 °C and NVOPF@rGO-500 °C samples.…”

Preferred coordination of polymers at MOFs enables improved lithium-ion battery anode performance

“…23 This designed multifunctional nanocomposite provides short paths to transport kinetics of Li + /e À ; its core-shell ZnO-C works as an electrolyte tank owing to its large space, and the entire SiOC network creates abundant active sites. 24 Fig. S3 (ESI †) depicts the transport kinetics of lithium-ions and electron transport kinetics during chargedischarge.…”

Direct conversion of solid g-C3N4 into metal-ended N-doped carbon nanotubes for rechargeable Zn–air batteries

“…Rechargeable Zn-air batteries (ZABs), as a promising alternative to the traditional secondary lithium-ion battery, 1,2 have received enormous attention in consideration of their high theoretical specific energy (1086 W h kg −1 ), low cost, use of aqueous solution as the electrolyte and environment friendly nature. [3][4][5][6][7] However, the sluggish kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) at the interface of air electrodes seriously limits the electrochemical performance of rechargeable ZABs.…”