[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Sodium-based dual-ion batteries (Na-DIBs) show a promising potential for large-scale energy storage applications due to the merits of environmental friendliness and low cost. However, Na-DIBs are generally subject to poor rate capability and cycling stability for the lack of suitable anodes to accommodate large Na+ ions. Herein, we propose a molecular grafting strategy to in situ synthesize tin pyrophosphate nanodots implanted in N-doped carbon matrix (SnP2O7@N-C), which exhibits a high fraction of active SnP2O7 up to 95.6 wt% and a low content of N-doped carbon (4.4 wt%) as the conductive framework. As a result, this anode delivers a high specific capacity ∼400 mAh g-1 at 0.1 A g-1, excellent rate capability up to 5.0 A g-1 and excellent cycling stability with a capacity retention of 92% after 1200 cycles under a current density of 1.5 A g-1. Further, pairing this anode with an environmentally friendly KS6 graphite cathode yields a SnP2O7@N-C||KS6 Na-DIB, exhibiting an excellent rate capability up to 30 C, good fast-charge/slow-discharge performance and long-term cycling life with a capacity retention of ∼96% after 1000 cycles at 20 C. This study provides a feasible strategy to develop high-performance anodes with high-fraction active materials for Na-based energy storage applications.

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Molecular grafting towards high-fraction active nanodots implanted in N-doped carbon for sodium dual-ion batteries.

Recent advances and challenges in biomass-derived porous carbon nanomaterials for supercapacitors

Recent Advances and Promise of MXene‐Based Nanostructures for High‐Performance Metal Ion Batteries

Rapid advancements in modern electronics have been starved of further breakthroughs to achieve high-energy, large-power, and long-running energy storage devices Carbon-based supercapacitors (CSs) are promising large-power systems that can store electrical energy at the interface between the carbonaceous electrode surface and adsorbed electrolyte layer However, commercial CSs using activated carbons suffer from limited energy densities in the organic electrolytes owing to sluggish mass diffusion and restricted charge accumulation To overcome these issues, significant efforts have been devoted toward increasing the energy storage of CSs by the exploration of both large-capacitance electrodes and high-potential electrolytes This paper reviews the recent advances made in the two core components (ie, electrodes and electrolytes) of CSs Firstly, we describe the involved energy storage mechanisms of CSs, followed by a brief overview of the key factors affecting the electrochemical performances Then, novel design concepts have been summarized that can be used to fabricate carbon-based electrodes, such as microporous carbons, mesoporous carbons, hierarchical porous carbons, functionalized carbons, and carbon composites Further, tailoring of the geometrical morphologies, pore structures, and surface functionalities can be discussed in pursuit of large-capacitance electrodes Furthermore, various types of aqueous and nonaqueous electrolytes, such as water-in-salt, organic media, ionic liquids, and (quasi-)solid-state electrolytes, have been systematically investigated to settle the water hydrolysis concern of traditional electrolytes Finally, the challenges in maximizing the synergistic effect between the electrodes and electrolytes are summarized, and we have proposed the future outlook for the development of advanced CSs

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Recent advances in carbon-based supercapacitors

Li-ion and K-ion batteries present their unique advantages of high energy density and low cost, respectively. It is a challenge to explore a universal anode with efficient electrochemical performance. Herein, a two-dimensional TiO2/reduced graphene oxide (RGO) composite was prepared by a facile hydrothermal method. TiO2 nanoparticles are transformed from Ti2C MXene and connect the RGO nanosheets to form a sheet-like structure. Serving as the anode material, the TiO2/RGO presents high capacity, remarkable rate ability and long cycling performance for both Li- and K-ion batteries. The superior electrochemical performance is attributed to the short ion diffusion path due to the small particle size (15–25 nm) and the highway for electron transport provided by RGO. In addition, RGO motivates the capacitive contribution, resulting in enhanced capacity and better rate performance. Meanwhile, the electrochemical kinetics of Li/K-ion storage was investigated by quantitative kinetics analysis. This work demonstrates a possibility to introduce the capacitive capacity to realize rapid ion storage and improve the cycling stability, providing a new strategy to design efficient electrodes for metal-ion batteries.

MXene-derived TiO2/reduced graphene oxide composite with an enhanced capacitive capacity for Li-ion and K-ion batteries

Lithium/potassium ion capacitors (LICs/PICs) have been proposed to bridge the performance gap between high-energy batteries and high-power capacitors. However, their development is hindered by the choice, electrochemical performance, and preparation technique of the battery-type anode materials. Herein, a nitrogen and phosphorus dual-doped multilayer graphene (NPG) material is designed and synthesized through an arc discharge process, using low-cost graphite and solid nitrogen and phosphorus sources. When employed as the anode material, NPG exhibits high capacity, remarkable rate capability, and stable cycling performance in both lithium and potassium ion batteries. This excellent electrochemical performance is ascribed to the synergistic effect of nitrogen and phosphorus doping, which enhances the electrochemical conductivity, provides a higher number of ion storage sites, and leads to increased interlayer spacing. Full carbon-based NPG‖LiPF6‖active carbon (AC) LICs and NPG‖KPF6‖AC PICs are assembled and show excellent electrochemical performance, with competitive energy and power densities. This work provides a route for the large-scale production of dual-doped graphene as a universal anode material for high-performance alkali ion batteries and capacitors.

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Nitrogen and Phosphorus Dual-Doped Multilayer Graphene as Universal Anode for Full Carbon-Based Lithium and Potassium Ion Capacitors

Aggregation-Resistant 3D Ti3C2Tx MXene with Enhanced Kinetics for Potassium Ion Hybrid Capacitors

Correction for ‘Ultrasmall-sized SnS nanosheets vertically aligned on carbon microtubes for sodium-ion capacitors with high energy density’ by Jing Zhao et al., J. Mater. Chem. A, 2019, 7, 4047–4054.

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Rong Hu

Papers

MXene-derived TiO2/reduced graphene oxide composite with an enhanced capacitive capacity for Li-ion and K-ion batteries

Nitrogen and Phosphorus Dual-Doped Multilayer Graphene as Universal Anode for Full Carbon-Based Lithium and Potassium Ion Capacitors

Aggregation-Resistant 3D Ti3C2Tx MXene with Enhanced Kinetics for Potassium Ion Hybrid Capacitors

Correction: Ultrasmall-sized SnS nanosheets vertically aligned on carbon microtubes for sodium-ion capacitors with high energy density

Synthesis of SnS2 Ultrathin Nanosheets as Anode Materials for Potassium Ion Batteries