Search

LiCoO 2 (LCO) has been functionally modified by mixed lithium ion and electron conducting LiAlPO 3.93 F 1.07 (LAPF) for the first time. Due to the unique coating layer with accepted Li-ion diffusion rate and electronic conductivity, the LAPF-coated LCO exhibits outstanding rate capability and cycle stability in the voltage range of 2.75–4.55 V. This material delivered a specific capacity of 206 mAh·g − 1 up to 0.5C rate and the capacity retention was 91.7% after 50 cycles, which is a remarkable improvement comparing with uncoated LCO (34.8%). It also exhibited superior rate capability with a discharge capacity of 161.4 mAh·g − 1 at 4C. The functionalized LAPF coating technique is an efficient approach to improve the electrochemical performance of LCO and can also be referred for other layered oxide cathode materials. [ABSTRACT FROM AUTHOR]

Abstract: Carbon nanotube (CNT) wired LiCo0.5Mn0.5PO4 nanocomposites were readily prepared using a facile one-pot hydrothermal approach. The prepared LiCo0.5Mn0.5PO4-CNT is composed of uniform nanoparticles of LiCo0.5Mn0.5PO4 intimately interconnected by CNT networks. The electrochemical test results show that the CNT networks play a critical role in maintaining electrical conduction and in ensuring electrode stability of LiCo0.5Mn0.5PO4-CNT upon cycling, thus leading to much enhanced electrochemical properties compared with neat LiCo0.5Mn0.5PO4. It is found that the LiCo0.5Mn0.5PO4-CNT composite exhibits a high capacity up to 151mAhg−1 and an energy density of 620mWhg−1, and maintain 92% of the initial capacity after 30 charge/discharge cycles, thereby indicating its potential for energy storage and conversion application. [Copyright &y& Elsevier]

Abstract: As an anode material for lithium-ion batteries (LIBs), silicon offers among the highest theoretical storage capacity, but is known to suffer from large structural changes and capacity fading during electrochemical cycling. Nanocomposites of silicon with carbon provide a potential material platform for resolving this problem. We report a spray-pyrolysis approach for synthesizing amorphous silicon–carbon nanocomposites from organic silane precursors. Elemental mapping shows that the amorphous silicon is uniformly dispersed in the carbon matrix. When evaluated as anode materials in LIBs, the materials exhibit highly, stable performance and excellent Coulombic efficiency for more than 150 charge discharge cycles at a charging rate of 1A/g. Post-mortem analysis indicates that the structure of the Si–C composite is retained after extended electrochemical cycling, confirming the hypothesis that better mechanical buffering is obtained when amorphous Si is embedded in a carbon matrix. [Copyright &y& Elsevier]

Abstract: Promising capacity retention (more than 92% of initial capacity after 100cycles), was exhibited in cells (graphite/xLi2MnO3·yLiMO2) with 2wt.% LiDFOB as additive. The outstanding cell performance was associated with the formation of stable solid electrolyte interface (SEI) film on the surface of electrodes derived from LiDFOB. Compared to the effect of the LiBOB additive, the main reason responsible for the greatly improved durability in LiDFOB added cells might be attributed to the more stable SEI film with lower interfacial resistance on the surface of anode. [Copyright &y& Elsevier]

Abstract: A novel C/Co composite with Co nanoparticles embedded in carbon matrix is synthesized firstly by pyrolysis of polymeric cobalt phthalocyanine (PcCo) at 700°C in argon atmosphere. This composite is investigated as an anode material for lithium ion batteries, indicating high tap density and excellent electrochemical performance. The C/Co electrode can retain a higher reversible capacity of over 600mAhg−1 at a current of 50mAg−1 after 40cycles and shows better rate capability and less hysteresis in comparison to carbon not containing Co. The significant improvement is attributed to the Co nanoparticles grown in-situ reaction with catalytic activity and high electrical conductivity. [Copyright &y& Elsevier]

Abstract: A unique ordered mesoporous Sn–C composite with Sn nanoparticles confined in carbon nanorods was prepared using SBA-15 as the template. This composite was employed as the anode material of Li-ion batteries, delivering excellent electrochemical properties of high reversible lithium storage capacity (554 mAh g−1 after 200 cycles) and great rate capability (as high as 5000mA g−1). [Copyright &y& Elsevier]

Abstract: In this paper, flower-like spinel Li4Ti5O12 consisting of nanosheets was synthesized by a hydrothermal process in glycol solution and following calcination. The as-prepared product was characterized by scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction and cyclic voltammetry. The capacity of the sample used as anode material for lithium ion battery was measured. This structured Li4Ti5O12 exhibited a high reversible capacity and an excellent rate capability of 165.8mAhg−1 at 8C, indicating potential application for lithium ion batteries with high rate performance and high capacity. [Copyright &y& Elsevier]

Abstract: Vanadium oxide nanotube materials were prepared by hydrothermal method and the factors that affect their electrochemical discharge–charge performance have been investigated. The morphology, structure and electrochemical properties of the VO x -NT materials depend on the post-treatment temperature and heat treatment media. The controlled post-treatment (200°C for 1h under Ar) produces a phase with improved capacity and reversibility, but the tubular shape is still well preserved. [Copyright &y& Elsevier]

Submicro-sized layered LiNi0.5Mn0.5O2 was synthesized via an improved solid-state reaction, in which at first a precursor mixed by nickel manganese double hydroxide with lithium hydroxide solution was prepared in order to make the fully contact between these materials, and then was calcined at different temperatures. The heat treatment process and the crystal structure of materials were investigated by DTA, TGA, and XRD methods. The SEM images show that the particles of layered LiNi0.5Mn0.5O2 are submicrometer in size. It was found that the layered LiNi0.5Mn0.5O2 synthesized at 750 °C for 24 h in oxygen atmosphere presents the best electrochemical performance, which delivers an initial discharge capacity of 153 mAh/g in the charge/discharge potential region (vs. Li) of 2.5–4.3 V, and exhibits good cycle stability. [Copyright &y& Elsevier]

Abstract: This work reports the facile synthesis of an amorphous FePO4 hollow nanosphere with tunable shell thickness for use as a cathode material in lithium ion batteries (LIBs). This material exhibits good electrochemical performance with a high specific capacity, a high rate capability, and good capacity retention upon cycling. [Copyright &y& Elsevier]