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mAh G (mah + g)

Distribution by Scientific Domains

Polymers and Materials Science	60%
Physics and Astronomy	40%

Selected Abstracts

High-Performance Carbon-LiMnPO4 Nanocomposite Cathode for Lithium Batteries

ADVANCED FUNCTIONAL MATERIALS, Issue 19 2010
Seung-Min Oh
Abstract A cathode material of an electrically conducting carbon-LiMnPO4 nanocomposite is synthesized by ultrasonic spray pyrolysis followed by ball milling. The effect of the carbon content on the physicochemical and electrochemical properties of this material is extensively studied. A LiMnPO4 electrode with 30 wt% acetylene black (AB) carbon exhibits an excellent rate capability and good cycle life in cell tests at 55 and 25 °C. This electrode delivers a discharge capacity of 158 mAh g,1 at 1/20 C, 126 mAh g,1 at 1 C, and 107 mAh g,1 at 2 C rate, which are the highest capacities reported so far for this type of electrode. Transmission electron microscopy and Mn dissolution results confirm that the carbon particles surrounding the LiMnPO4 protect the electrode from HF attack, and thus lead to a reduction of the Mn dissolution that usually occurs with this electrode. The improved electrochemical properties of the C-LiMnPO4 electrode are also verified by electrochemical impedance spectroscopy. [source]

Nest-like Silicon Nanospheres for High-Capacity Lithium Storage,

ADVANCED MATERIALS, Issue 22 2007
H. Ma
Nest-like Si nanospheres and their highly reversible lithium storage (3952 mAh g,1 at 100 mA g,1) and excellent high-rate capability (3052 mAh g,1 at 2000 mA g,1) are reported (see figure). This result suggests that the as-prepared nest-like Si nanospheres are promising candidates as the anode materials of rechargeable Li-ion batteries. [source]

Fabrication and properties of crosslinked poly(propylene carbonate maleate) gel polymer electrolyte for lithium-ion battery

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2010
Xiaoyuan Yu
Abstract The poly(propylene carbonate maleate) (PPCMA) was synthesized by the terpolymerization of carbon dioxide, propylene oxide, and maleic anhydride. The PPCMA polymer can be readily crosslinked using dicumyl peroxide (DCP) as crosslinking agent and then actived by absorbing liquid electrolyte to fabricate a novel PPCMA gel polymer electrolyte for lithium-ion battery. The thermal performance, electrolyte uptake, swelling ratio, ionic conductivity, and lithium ion transference number of the crosslinked PPCMA were then investigated. The results show that the Tg and the thermal stability increase, but the absorbing and swelling rates decrease with increasing DCP amount. The ionic conductivity of the PPCMA gel polymer electrolyte firstly increases and then decreases with increasing DCP ratio. The ionic conductivity of the PPCMA gel polymer electrolyte with 1.2 wt % of DCP reaches the maximum value of 8.43 × 10,3 S cm,1 at room temperature and 1.42 × 10,2 S cm,1 at 50°C. The lithium ion transference number of PPCMA gel polymer electrolyte is 0.42. The charge/discharge tests of the Li/PPCMA GPE/LiNi1/3Co1/3Mn1/3O2 cell were evaluated at a current rate of 0.1C and in voltage range of 2.8,4.2 V at room temperature. The results show that the initial discharge capacity of Li/PPCMA GPE/LiNi1/3Co1/3Mn1/3 O2 cell is 115.3 mAh g,1. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]

Preparation of tin nanocomposite as anode material by molten salts method and its application in lithium ion batteries

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 11 2009
Mohd Faiz Hassan
Abstract A nanocomposite material (SnO2Co3O4) has been synthesized as an anode material for lithium-ion batteries by the molten salt method. Characterization by X-ray diffraction (XRD) and transmission electron microscopy (TEM) showed that the composite has a small particle size. The electrochemical performance was examined, including the charge,discharge and cycling properties. The experimental results showed that the sample containing the highest amount of Co3O4 compound exhibited a specific capacity of 355,mAh g,1 after 40 cycles, with cycling at 70,mA g,1 (35.2% higher than for the sample containing a lower amount of Co3O4). It seems that increasing the amount of Co3O4 can give good capacity retention and high specific capacity. [source]

Effect of palladium addition on the electrochemical properties of amorphous 2Mg + 3d alloys doped by nickel atoms (3d = Fe, Ni)

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 5 2010
Maciej Jarzebski
Abstract Amorphous 2Mg+ 3d/x wt% Ni materials were prepared by mechanical alloying (MA) of Mg and 3d elemental powders (3d = Fe, Ni x =0, 100 and 200 wt.%) under high purity argon atmosphere in SPEX 8000 Mixer Mill. The effect of the Ni addition on the electrochemical properties of the synthesized nanostructured alloys was investigated in details. The discharge capacity of amorphous 2Mg+Fe (Ni) high energy ball milled with Ni was improved. With increasing nickel content in the studied 2Mg+Fe (Ni) materials, at first cycle, the discharge capacity increases first and then decreases, and for example, for x = 100 in 2Mg+Fe reaches a maximum value of 155 mAh g,1. Additionally, when coated with palladium, the discharge capacity of an amorphous 2Mg+Fe (Ni) powders was increased as well. The catalytic elements (Ni, Pd) were distributed on the surface of ball milled alloy particles homogenously and role of these particles is to catalyze the dissociation of molecular hydrogen on the surface of studied alloy. Mechanical coating with palladium effectively reduced the degradation rate of the studied electrode materials. Compared to that of the uncoated powders, the degradation of the coated was suppressed. The amorphous Mg-based hydrides offer a breakthrough in prospects for practical applications (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]