Most potassium‐ion battery (PIB) cathode materials have deficient structural stability because of the huge radius of potassium ion, leading to inferior cycling performance. We report the controllable ...synthesis of a novel low‐strain phosphate material K3(VO)(HV2O3)(PO4)2(HPO4) (denoted KVP) nanorulers as an efficient cathode for PIBs. The as‐synthesized KVP nanoruler cathode exhibits an initial reversible capacity of 80.6 mAh g−1 under 20 mA g−1, with a large average working potential of 4.11 V. It also manifests an excellent rate property of 54.4 mAh g−1 under 5 A g−1, with a high capacity preservation of 92.1 % over 2500 cycles. The outstanding potassium storage capability of KVP nanoruler cathode originates from a low‐strain K+ uptake/removal mechanism, inherent semiconductor characteristic, and small K+ migration energy barrier. The high energy density and prolonged cyclic stability of KVP nanorulers//polyaniline‐intercalated layered titanate full battery verifies the superiority of KVP nanoruler cathode in PIBs.
A low‐strain phosphate cathode material K3(VO)(HV2O3)(PO4)2(HPO4) (KVP) nanoruler is synthesized by a facile solvothermal approach. The KVP nanorulers manifest high discharge voltage, superior rate capability, and ultralong cyclic life as a cathode material for potassium‐ion batteries (PIBs). This work would provide guidance to exploit high‐performance PIB cathode materials.
Ultra‐uniform SnOx/carbon nanohybrids for lithium‐ion batteries are successfully prepared by solvent replacement and subsequent electrospinning. The resulting 1D nanostructure with Sn‐N bonding ...between the SnOx and N‐containing carbon nanofiber matrix can not only tolerate the substantial volume change and suppress the aggregation of SnOx, but also enhances the transport of both electrons and ions for the embedded SnOx, thus leading to high cycling performance and rate capability.
A facile method to synthesize a MoS(2) nanosheet-graphene nanosheet hybrid has been developed via the combination of a lithiation-assisted exfoliation process and a hydrazine monohydrate vapour ...reduction technique. The as-obtained nanosheet-nanosheet hybrid is more robust and exhibits much improved cycle life (>700), which make it an efficient morphological solution to the stable lithium storage problem of nanomaterials.
In contrast to the extensive investigation of the electrochemical performance of conventional carbon materials in sodium-ion batteries, there has been scarcely any study of sodium storage property of ...fluorine-doped carbon. Here we report for the first time the application of fluorine-doped carbon particles (F-CP) synthesized through pyrolysis of lotus petioles as anode materials for sodium-ion batteries. Electrochemical tests demonstrate that the F-CP electrode delivers an initial charge capacity of 230 mA h g–1 at a current density of 50 mA g–1 between 0.001 and 2.8 V, which greatly outperforms the corresponding value of 149 mA h g–1 for the counterpart banana peels-derived carbon (BPC). Even under 200 mA g–1, the F-CP electrode could still exhibit a charge capacity of 228 mA h g–1 with initial charge capacity retention of 99.1% after 200 cycles compared to the BPC electrode with 107 mA h g–1 and 71.8%. The F-doping and the large interlayer distance as well as the disorder structure contribute to a lowering of the sodium ion insertion–extraction barrier, thus promoting the Na+ diffusion and providing more active sites for Na+ storage. In specific, the F-CP electrode shows longer low-discharge-plateau and better kinetics than does the common carbon-based electrode. The unique electrochemical performance of F-CP enriches the existing knowledge of the carbon-based electrode materials and broadens avenues for rational design of anode materials in sodium-ion batteries.
Tin possesses a high theoretical specific capacity as anode materials for Li-ion batteries, and considerable efforts have been contributed to mitigating the capacity fading along with its huge volume ...expansion during lithium insertion and extraction processes, mainly through nanostructured material design. Herein, we present Sn nanoparticles encapsulated in nitrogen-doped graphene sheets through heat-treatment of the SnO2 nanocrystals/nitrogen-doped graphene hybrid. The specific architecture of the as-prepared Sn@N-RGO involves three advantages, including a continuous graphene conducting network, coating Sn surface through Sn–N and Sn–O bonding generated between Sn nanoparticles and graphene, and porous and flexible structure for accommodating the large volume changes of Sn nanoparticles. As an anode material for lithium-ion batteries, the hybrid exhibits a reversible capacity of 481 mA h g–1 after 100 cycles under 0.1 A g–1 and a charge capacity as high as 307 mA h g–1 under 2 A g–1.
An electrostatic attraction directed self‐assembly approach for uniform dispersion of Si nanoparticles between two layers of graphene sheets has been developed. The as‐obtained Si‐NP@G nanocomposite ...exhibits much improved cycling performance and excellent rate capability.
Tin disulfide (SnS2) is a promising anode material for sodium-ion batteries because of its high specific capacity. However, the low conductivity and large volume change during reaction with Na+ ions ...greatly limit its practical application. Herein, a multistep templating method has been exploited for the rational design and synthesis of SnS2 nanosheets confined in carbon nanotubes (SnS2@CNTs). To demonstrate the universality of this method, SnS2 nanosheets confined in carbon nanoboxes (SnS2@CNBs) and hollow carbon nanospheres (SnS2@CNSs) have also been synthesized by simply changing the template in the reaction system. Due to their unique structural merits, the SnS2@CNTs, SnS2@CNBs, and SnS2@CNSs show improved sodium storage performance in terms of high specific capacity, good cycling stability, and superior rate capability.
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•SnS2 nanosheets are confined in various hollow carbon nanostructures•Ultrathin SnS2 nanosheets ensure efficient capacitive sodium storage•SnS2-carbon electrodes manifest excellent electrochemical sodium storage performance
Sodium-ion batteries (SIBs) have attracted ever-growing attention as an alternative to lithium-ion batteries in view of the abundant resources and low cost of sodium. One major challenge for SIBs exists in developing efficient anode materials. Tin disulfide (SnS2) is a promising anode material for SIBs because of its high theoretical capacity. However, the low conductivity and huge volume expansion during reaction with Na+ ions significantly hamper its practical application. Here, we develop a facile templating method to effectively confine ultrathin SnS2 nanosheets in carbon nanotubes (SnS2@CNTs), carbon nanoboxes (SnS2@CNBs), and hollow carbon nanospheres (SnS2@CNSs). Benefiting from their unique structural advantages, these SnS2-carbon nanohybrids manifest high specific capacity, good cycling stability, and excellent rate capability. This work might enlighten scientists to exploit high-performance SIB anodes so that SIBs can be used in large-scale energy storage in the near future.
Sodium-ion batteries (SIBs) have attracted enormous attention as an alternative to lithium-ion batteries (LIBs). Recent studies on SIB cathodes have demonstrated performances comparable with their LIB counterparts. One major challenge for SIBs thus resides in exploiting suitable anode materials. Here, we develop a multistep templating method to confine SnS2 nanosheets in different carbon hollow structures including nanotubes, nanoboxes, and hollow nanospheres. Benefiting from their unique structural merits, these SnS2-carbon nanohybrids manifest excellent sodium storage properties.
MoS(2)@CMK-3 nanocomposite consisting of confined nanosized MoS(2) in CMK-3 carbon matrix exhibits much improved cycling performance and rate capability due to the enlarged interlayer distance and ...favorable conductivity.
Covalent organic frameworks (COFs), as highly tunable porous crystalline materials, have promising applications in potassium-ion batteries (PIBs) due to their abundant charge carrier transport ...channels and excellent structural stability. However, the excessive stacking of interlayer electron clouds makes it difficult to expose internal active sites. Strategies to design functional COFs with controllable morphology and copious active sites are promising but still challenging. Herein, by utilizing the condensation between 1,3,5-triformylbenzene (TFB) and p-phenylenediamine (PPD) and using amino-modified SiO2 nanospheres as templates, we synthesize core-shell NH2-SiO2@TP-COF. Through NaOH etching of NH2-SiO2@TP-COF, we obtain imine-based TP-COF hollow nanospheres, which shows excellent potassium storage performance when applied to the anode for PIBs. Ex-situ analysis and density functional theory calculations reveal that CN groups and benzenes are active sites for K+ storage.
Imine-based covalent organic framework hollow nanospheres (TP-COF HSs) with ordered porous architecture and good chemical stability were synthesized using amino-modified SiO2 nanosphere template. The as-obtained TP-COF HSs exhibit a high capacity of 336 mAh/g at 0.1 A/g after 100 cycles and a superior rate capacity of 160 mAh/g at 1 A/g for potassium storage.
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Organized chaos: A highly disordered carbon composite is synthesized through self‐assembly and subsequent pyrolysis. When evaluated as an anode material for room‐temperature sodium‐ion batteries, the ...as‐obtained carbon delivers superior electrochemical characteristics in terms of reversible capacity, cycling performance, and rate capability.
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