[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Energy production and storage technologies have attracted a great deal of attention for day-to-day applications. In recent decades, advances in lithium-ion battery (LIB) technology have improved living conditions around the globe. LIBs are used in most mobile electronic devices as well as in zero-emission electronic vehicles. However, there are increasing concerns regarding load leveling of renewable energy sources and the smart grid as well as the sustainability of lithium sources due to their limited availability and consequent expected price increase. Therefore, whether LIBs alone can satisfy the rising demand for small- and/or mid-to-large-format energy storage applications remains unclear. To mitigate these issues, recent research has focused on alternative energy storage systems. Sodium-ion batteries (SIBs) are considered as the best candidate power sources because sodium is widely available and exhibits similar chemistry to that of LIBs; therefore, SIBs are promising next-generation alternatives. Recently, sodiated layer transition metal oxides, phosphates and organic compounds have been introduced as cathode materials for SIBs. Simultaneously, recent developments have been facilitated by the use of select carbonaceous materials, transition metal oxides (or sulfides), and intermetallic and organic compounds as anodes for SIBs. Apart from electrode materials, suitable electrolytes, additives, and binders are equally important for the development of practical SIBs. Despite developments in electrode materials and other components, there remain several challenges, including cell design and electrode balancing, in the application of sodium ion cells. In this article, we summarize and discuss current research on materials and propose future directions for SIBs. This will provide important insights into scientific and practical issues in the development of SIBs.

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Sodium-ion batteries: present and future

Metal Oxides and Oxysalts as Anode Materials for Li Ion Batteries

Since its first isolation in 2004, graphene has become one of the hottest topics in the field of materials science, and its highly appealing properties have led to a plethora of scientific papers. Among the many affected areas of materials science, this 'graphene fever' has influenced particularly the world of electrochemical energy-storage devices. Despite widespread enthusiasm, it is not yet clear whether graphene could really lead to progress in the field. Here we discuss the most recent applications of graphene - both as an active material and as an inactive component - from lithium-ion batteries and electrochemical capacitors to emerging technologies such as metal-air and magnesium-ion batteries. By critically analysing state-of-the-art technologies, we aim to address the benefits and issues of graphene-based materials, as well as outline the most promising results and applications so far.

The role of graphene for electrochemical energy storage

This Review focuses on noncovalent functionalization of graphene and graphene oxide with various species involving biomolecules, polymers, drugs, metals and metal oxide-based nanoparticles, quantum dots, magnetic nanostructures, other carbon allotropes (fullerenes, nanodiamonds, and carbon nanotubes), and graphene analogues (MoS2, WS2). A brief description of π–π interactions, van der Waals forces, ionic interactions, and hydrogen bonding allowing noncovalent modification of graphene and graphene oxide is first given. The main part of this Review is devoted to tailored functionalization for applications in drug delivery, energy materials, solar cells, water splitting, biosensing, bioimaging, environmental, catalytic, photocatalytic, and biomedical technologies. A significant part of this Review explores the possibilities of graphene/graphene oxide-based 3D superstructures and their use in lithium-ion batteries. This Review ends with a look at challenges and future prospects of noncovalently modified graph...

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Noncovalent Functionalization of Graphene and Graphene Oxide for Energy Materials, Biosensing, Catalytic, and Biomedical Applications

Author(s): Qu, Baihua; Ma, Chuze; Ji, Ge; Xu, Chaohe; Xu, Jing; Meng, Ying Shirley; Wang, Taihong; Lee, Jim Yang | Abstract: A layered SnS2-reduced graphene oxide (SnS2-RGO) composite is prepared by a facile hydrothermal route and evaluated as an anode material for sodium-ion batteries (NIBs). The measured electrochemical properties are a high charge specific capacity (630 mAh g-1 at 0.2 A g-1) coupled to a good rate performance (544 mAh g-1 at 2 A g-1) and long cycle-life (500 mAh g-1 at 1 A g -1 for 400 cycles). © 2014 WILEY-VCH Verlag GmbH a Co. KGaA, Weinheim.

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Layered SnS2-Reduced Graphene Oxide Composite – A High-Capacity, High-Rate, and Long-Cycle Life Sodium-Ion Battery Anode Material

A facile hydrothermal method is developed for large-scale production of three-dimensional (3D) hierarchical porous nickel cobaltate nanowire cluster arrays derived from nanosheet arrays with robust adhesion on Ni foam. Based on the morphology evolution upon reaction time, a possible formation process is proposed. The role of NH4F in formation of the structure has also been investigated based on different NH4F amounts. This unique structure significantly enhances the electroactive surface areas of the NiCo2O4 arrays, leading to better interfacial/chemical distributions at the nanoscale, fast ion and electron transfer and good strain accommodation. Thus, when it is used for supercapacitor testing, a specific capacitance of 1069 F g−1 at a very high current density of 100 A g−1 was obtained. Even after more than 10 000 cycles at various large current densities, a capacitance of 2000 F g−1 at 10 A g−1 with 93.8% retention can be achieved. It also exhibits a high-power density (26.1 kW kg−1) at a discharge current density of 80 A g−1. When used as an anode material for lithium-ion batteries (LIBs), it presents a high reversible capacity of 976 mA h g−1 at a rate of 200 mA g−1 with good cycling stability and rate capability. This array material is rarely used as an anode material. Our results show that this unique 3D hierarchical porous nickel cobaltite is promising for electrochemical energy applications.

High-performance supercapacitor and lithium-ion battery based on 3D hierarchical NH4F-induced nickel cobaltate nanosheet-nanowire cluster arrays as self-supported electrodes.

In this paper, three dimensional (3D) uniform ZnCo-glycolate precursor microspheres composed of nanosheets were successfully synthesized via a facile ethylene glycol (EG) mediated solvothermal method. Through moderate calcination of the as-synthesized ZnCo-glycolate precursor, they could be converted into uniform mesoporous ZnCo2O4 microspheres with surrounding nanoparticles. The obtained samples were systematically characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and N2 adsorption–desorption. The results demonstrated that tuning of the surface texture and the pore size of the ZnCo2O4 products were very significant in Li-ion batteries (LIBs). The uniform mesoporous ZnCo2O4 microspheres exhibit excellent high specific capacity, superior rate capability, and enhanced cycling performance. At a current density of 100 mA g−1, the uniform mesoporous ZnCo2O4 microspheres exhibited excellent initial specific capacity of 1332 mAh g−1. The capacity maintain at 721 mAh g−1 after 80 discharge–charge cycles. Even as current density reached to 1000 mA g−1, the initial specific capacity still showed 937 mAh g−1 and the discharge capacity of 432 mAh g−1 was retained after 40 cycles.

Facile synthesis of uniform mesoporous ZnCo2O4 microspheres as a high-performance anode material for Li-ion batteries

Graphene improving lithium-ion battery performance by construction of NiCo2O4/graphene hybrid nanosheet arrays

Two-dimensional nanosheets can leverage on their open architecture to support facile insertion and removal of Li+ as lithium-ion battery electrode materials. In this study, two two-dimensional nanosheets with complementary functions, namely nitrogen-doped graphene and few-layer WS2, were integrated via a facile surfactant-assisted synthesis under hydrothermal conditions. The layer structure and morphology of the composites were confirmed by X-ray diffraction, scanning electron microscopy and high-resolution transmission microscopy. The effects of surfactant amount on the WS2 layer number were investigated and the performance of the layered composites as high energy density lithium-ion battery anodes was evaluated. The composite formed with a surfactant : tungsten precursor ratio of 1 : 1 delivered the best cyclability (average of only 0.08% capacity fade per cycle for 100 cycles) and good rate performance (80% capacity retention with a 50-fold increase in current density from 100 mA g−1 to 5000 mA g−1), and may find uses in power-oriented applications.

Baihua Qu

Papers

Layered SnS2-Reduced Graphene Oxide Composite – A High-Capacity, High-Rate, and Long-Cycle Life Sodium-Ion Battery Anode Material

High-performance supercapacitor and lithium-ion battery based on 3D hierarchical NH4F-induced nickel cobaltate nanosheet-nanowire cluster arrays as self-supported electrodes.

Facile synthesis of uniform mesoporous ZnCo2O4 microspheres as a high-performance anode material for Li-ion batteries

Graphene improving lithium-ion battery performance by construction of NiCo2O4/graphene hybrid nanosheet arrays

In situ nitrogenated graphene–few-layer WS2 composites for fast and reversible Li+ storage