[Liu, Chang; Li, Feng; Ma, Lai-Peng; Cheng, Hui-Ming] Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Peoples R China.;Cheng, HM (reprint author), Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, 72 Wenhua Rd, Shenyang 110016, Peoples R China;cheng@imr.ac.cn

Advanced Materials for Energy Storage

Metal Oxides and Oxysalts as Anode Materials for Li Ion Batteries

[Wu, Zhong-Shuai; Ren, Wencai; Wen, Lei; Gao, Libo; Zhao, Jinping; Chen, Zongping; Zhou, Guangmin; Li, Feng; Cheng, Hui-Ming] Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Peoples R China;Ren, WC (reprint author), Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, 72 Wenhua Rd, Shenyang 110016, Peoples R China;wcren@imraccn cheng@imraccn

Graphene Anchored with Co 3 O 4 Nanoparticles as Anode of Lithium Ion Batteries with Enhanced Reversible Capacity and Cyclic Performance

Despite the imminent commercial introduction of Li-ion batteries in electric drive vehicles and their proposed use as enablers of smart grids based on renewable energy technologies, an intensive quest for new electrode materials that bring about improvements in energy density, cycle life, cost, and safety is still underway. This Progress Report highlights the recent developments and the future prospects of the use of phases that react through conversion reactions as both positive and negative electrode materials in Li-ion batteries. By moving beyond classical intercalation reactions, a variety of low cost compounds with gravimetric specific capacities that are two-to-five times larger than those attained with currently used materials, such as graphite and LiCoO(2), can be achieved. Nonetheless, several factors currently handicap the applicability of electrode materials entailing conversion reactions. These factors, together with the scientific breakthroughs that are necessary to fully assess the practicality of this concept, are reviewed in this report.

Beyond Intercalation-Based Li-Ion Batteries: The State of the Art and Challenges of Electrode Materials Reacting Through Conversion Reactions

In this paper, the use of nanostructured anode materials for rechargeable lithium-ion batteries (LIBs) is reviewed. Nanostructured materials such as nano-carbons, alloys, metal oxides, and metal sulfides/nitrides have been used as anodes for next-generation LIBs with high reversible capacity, fast power capability, good safety, and long cycle life. This is due to their relatively short mass and charge pathways, high transport rates of both lithium ions and electrons, and other extremely charming surface activities. In this review paper, the effect of the nanostructure on the electrochemical performance of these anodes is presented. Their synthesis processes, electrochemical properties, and electrode reaction mechanisms are also discussed. The major goals of this review are to give a broad overview of recent scientific researches and developments of anode materials using novel nanoscience and nanotechnology and to highlight new progresses in using these nanostructured materials to develop high-performance LIBs. Suggestions and outlooks on future research directions in this field are also given.

Recent developments in nanostructured anode materials for rechargeable lithium-ion batteries

Over the past decades, a worldwide effort has been made to search for alternative anode materials of lithium batteries for improving their energy density and safety. It has been found that 3d transition metal oxides such as nickel oxide, cobalt oxide, and iron oxide exhibit reversible capacities about three times larger than those of graphite (372 mAh g) at a relative low potential, which greatly spurs the rapid development in this field. Among them, cobalt oxides (Co3O4 and CoO) have shown the highest capacity (700 mAh g) and best cycle performance (93.4 % of initial capacity was retained after 100 cycles), compared with nickel oxide (NiO) and iron oxides (Fe2O3 and Fe3O4). [3] In recent years, the nanostructured materials have attracted great interest in the application of anode or cathode materials for lithium batteries because of their high surface-to-volume ratio and short path length for Li transport. As a result, it is believed that the Co3O4 nanomaterials can exhibit the superior Li-battery performance. Previously, several Co3O4 nanostructures such as nanoparticles, nanowires, and nanotubes were prepared by different methods. Among them, the nanotubes have been considered one of the most promising structures for lithium batteries due to their higher surface-to-volume ratio than other one-dimensional nanostructures such as nanowires and more difficult for aggregation in comparison with nanoparticles. By far, there is little literature about the synthesis and application of Co3O4 nanotubes for lithium batteries. For example, Chen et al. synthesized the Co3O4 nanotubes via the anodic aluminum oxide (AAO) template route and applied them for lithium batteries with the capacity of about 800 mAh g at the current density of 50 mA g. However, there are some disadvantages for the AAO template assisted approach to synthesize metal oxide nanotubes, which restrict their application in Libattery. Firstly, the mass production of metal oxide nanotubes prepared by such an approach is impracticable, which is one of the bottlenecks for their wide applications. Secondly, it is very difficult to completely remove the nanoporous alumina template. Thirdly, the diameters of metal oxide nanotubes prepared by such an approach are usually larger than 100 nm. Recently, carbon nanotubes (CNTs) have been considered to be an ideal template for the synthesis of metal oxide nanotubes due to the mass production, being easily removed and small diameter. For example, Liu et al. reported the synthesis of Fe2O3/CNTs core-shell nanostructures and polycrystalline Fe2O3 nanotubes by supercritical fluids approach using CNTs as templates. Unfortunately, the high temperature and pressure were needed in this approach. In addition, metal oxide/ CNTs core-shell nanostructures and metal oxide nanotubes were also achieved by CNT-template assisted chemical vapor deposition (CVD), which operated at high temperature and, moreover, only deposited oxides on the top surface of CNTs. Furthermore, metal oxide/CNTs core-shell nanostructures were also fabricated by chemical precipitation method. However, the formation of metal oxide nanoparticles in the solution or metal oxide with very large grain size on the surface of CNTs was inevitable in this approach, which made it difficult to form metal oxide nanotubes after oxidation of CNTs. Very recently, we have developed a novel approach to synthesizing the porous and polycrystalline In2O3 nanotubes by layer-by-layer assembly on CNT templates in combination with subsequent calcinations, which exhibit superior gas sensing performance. Herein, we report a novel sonochemistry method to synthesizing CNTs-CoOx nanocables derived from Co4(CO)12 clusters on CNT templates at room temperature and subsequent transformation into uniform porous Co3O4 nanotubes by the calcination. Moreover, the assynthesized porous Co3O4 nanotubes have been applied in anode materials for lithium batteries, which exhibit the superior performance and thus promising application. Firstly, Co4(CO)12 and CNTs were mixed in hexane and sonicated for 1 h at room temperature. During the sonication, Co4(CO)12 can be readily decomposed to Co and CO, as shown in Reaction 1. Secondly, Co atom can be rapidly oxidized into CoOx due to the oxygen atmosphere in the solution, as illustrated in Reaction 2. Thirdly, CoOx with positive charge can be compactly deposited on the surface of CNTs C O M M U N IC A IO N

Porous Co3O4 Nanotubes Derived From Co4(CO)12 Clusters on Carbon Nanotube Templates : A Highly Efficient Material For Li-Battery Applications

Single-crystalline, monodisperse copper sulfide nanocrystals with controlled sizes, shapes, and phases were successfully synthesized via a simple, low-cost, and environmentally friendly chemical reaction of CuCl2 and S in oleylamine at 100−180 °C. It was found that the molar ratios of [CuCl2]:[S] played the critical role for the control of the sizes, shapes, and phases of copper sulfide nanocrystals. The hexagonal CuS nanodisks, hexagonal CuS nanoribbons consisting of face-to-face stacked nanodisks, and monoclinic Cu1.75S nanoribbons consisting of face-to-face stacked nanodisks were obtained when the molar ratios of [CuCl2]:[S] were 1:1, 2:3, and 2:1, respectively. It was believed that the van der Waals force and dipole−dipole interaction were responsible for the self-assembly of copper sulfide nanodisks. Finally, the copper sulfide nanocrystals were characterized by transmission electron microscopy, high-resolution transmission electron micrscopy, X-ray diffraction, and Fourier transform infrared, and it...

Yiqiang Zhang

Papers

Porous Co3O4 Nanotubes Derived From Co4(CO)12 Clusters on Carbon Nanotube Templates : A Highly Efficient Material For Li-Battery Applications

Phase-Selective Synthesis and Self-Assembly of Monodisperse Copper Sulfide Nanocrystals