In-situ rooting ZnSe/N-doped hollow carbon architectures as high-rate and long-life anode materials for half/full sodium-ion and potassium-ion batteries

Kang

Park

et al. 2020

Small

Potassium‐ion batteries (KIBs) are considered as promising alternatives to lithium‐ion batteries owing to the abundance and affordability of potassium. However, the development of suitable electrode materials that can stably store large‐sized K ions remains a challenge. This study proposes a facile impregnation method for synthesizing ultrafine cobalt–iron bimetallic selenides embedded in hollow mesoporous carbon nanospheres (HMCSs) as superior anodes for KIBs. This involves loading metal precursors into HMCS templates using a repeated “drop and drying” process followed by selenization at various temperatures, facilitating not only the preparation of bimetallic selenide/carbon composites but also controlling their structures. HMCSs serve as structural skeletons, conductive templates, and vehicles to restrain the overgrowth of bimetallic selenide particles during thermal treatment. Various analysis strategies are employed to investigate the charge–discharge mechanism of the new bimetallic selenide anodes. This unique‐structured composite exhibits a high discharge capacity (485 mA h g−1 at 0.1 A g−1 after 200 cycles) and enhanced rate capability (272 mA h g−1 at 2.0 A g−1) as a promising anode material for KIBs. Furthermore, the electrochemical properties of various nanostructures, from hollow to frog egg‐like structures, obtained by adjusting the selenization temperature, are compared.

Section: Resultsmentioning

confidence: 99%

Conversion Reaction Mechanism of Ultrafine Bimetallic Co‐Fe Selenides Embedded in Hollow Mesoporous Carbon Nanospheres and Their Excellent K‐Ion Storage Performance

Kang

Park

et al. 2020

Small

“…As emerging anode materials for KIBs, transition metal selenides have been intensively studied in consideration of their high specific theoretical capacities and narrow bandgap semiconductor properties [6,7]. However, two major obstacles still require to be overcome: their large volume expansion upon potassiation and their low electrical conductivity.…”

Section: Introductionmentioning

confidence: 99%

MOF-Derived CoSe2@N-Doped Carbon Matrix Confined in Hollow Mesoporous Carbon Nanospheres as High-Performance Anodes for Potassium-Ion Batteries

Kang

2020

Nano-Micro Lett.

In this work, a novel vacuum-assisted strategy is proposed to homogenously form Metal–organic frameworks within hollow mesoporous carbon nanospheres (HMCSs) via a solid-state reaction. The method is applied to synthesize an ultrafine CoSe2 nanocrystal@N-doped carbon matrix confined within HMCSs (denoted as CoSe2@NC/HMCS) for use as advanced anodes in high-performance potassium-ion batteries (KIBs). The approach involves a solvent-free thermal treatment to form a Co-based zeolitic imidazolate framework (ZIF-67) within the HMCS templates under vacuum conditions and the subsequent selenization. Thermal treatment under vacuum facilitates the infiltration of the cobalt precursor and organic linker into the HMCS and simultaneously transforms them into stable ZIF-67 particles without any solvents. During the subsequent selenization process, the “dual confinement system”, composed of both the N-doped carbon matrix derived from the organic linker and the small-sized pores of HMCS, can effectively suppress the overgrowth of CoSe2 nanocrystals. Thus, the resulting uniquely structured composite exhibits a stable cycling performance (442 mAh g−1 at 0.1 A g−1 after 120 cycles) and excellent rate capability (263 mAh g−1 at 2.0 A g−1) as the anode material for KIBs.

“…Alternatively, novel energy storage techniques, including sodium-ion batteries (NIBs), potassiumion batteries (KIBs), magnesium-ion batteries (MIBs), and aluminum-ion batteries (AIBs), are getting numerous attentions due to the natural abundance and low cost of the metal resources and great progresses have been achieved in recent years. [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] Among the various battery technologies, KIBs is considered as one of the most promising battery technologies Developing low-cost, high-capacity, high-rate, and robust earth-abundant electrode materials for energy storage is critical for the practical and scalable application of advanced battery technologies. Herein, the first example of synthesizing 1D peapod-like bimetallic Fe 2 VO 4 nanorods confined in N-doped carbon porous nanowires with internal void space (Fe 2 VO 4 ⊂NC nanopeapods) as a high-capacity and stable anode material for potassium-ion batteries (KIBs) is reported.…”

Section: Introductionmentioning

confidence: 99%

Confined Fe₂VO₄⊂Nitrogen‐Doped Carbon Nanowires with Internal Void Space for High‐Rate and Ultrastable Potassium‐Ion Storage

Advanced Energy Materials

Zhang

et al. 2019

Developing low‐cost, high‐capacity, high‐rate, and robust earth‐abundant electrode materials for energy storage is critical for the practical and scalable application of advanced battery technologies. Herein, the first example of synthesizing 1D peapod‐like bimetallic Fe2VO4 nanorods confined in N‐doped carbon porous nanowires with internal void space (Fe2VO4⊂NC nanopeapods) as a high‐capacity and stable anode material for potassium‐ion batteries (KIBs) is reported. The peapod‐like Fe2VO4⊂NC nanopeapod heterostructures with interior void space and external carbon shell efficiently prevent the aggregation of the active materials, facilitate fast transportation of electrons and ions, and accommodate volume variation during the cycling process, which substantially boosts the rate and cycling performance of Fe2VO4. The Fe2VO4⊂NC electrode exhibits high reversible specific depotassiation capacity of 380 mAh g−1 at 100 mA g−1 after 60 cycles and remarkable rate capability as well as long cycling stability with a high capacity of 196 mAh g−1 at 4 A g−1 after 2300 cycles. The first‐principles calculations reveal that Fe2VO4⊂NC nanopeapods have high ionic/electronic conductivity characteristics and low diffusion barriers for K+‐intercalation. This study opens up new way for investigating high‐capacity metal oxide as high‐rate and robust electrode materials for KIBs.