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Abstract: A three-dimensional macroporous Cu/SnO2 composite anode sheet for lithium ion batteries was prepared via a novel method that is based on selective reduction of metal oxides at appropriate temperatures. SnO2 particles were imbedded on the Cu particles within the three-dimensionally interconnected Cu substrate, and the whole composite sheet was used directly as an electrode without adding extra conductive carbons and binders. Compared with the SnO2-based electrode prepared via the conventional tape-casting method on Cu foil, the porous Cu/SnO2 composite electrode shows significantly improved battery performance. This methodology produces limited wastes and is also adaptable to many other materials. It is a promising approach to make macroporous electrode for Li-ion batteries. [Copyright &y& Elsevier]

Abstract: To improve the performance of LiFePO4, single phase Li1−x Na x FePO4/C (x =0, 0.01, 0.03, 0.05) samples are synthesized by in situ polymerization restriction–carbonthermal reduction method. The effects of Na doping are studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results indicate that doped Na ion does not destroy the lattice structure of LiFePO4, while enlarges the lattice volume. Electrochemical test results show that the Li0.97Na0.03FePO4/C sample exhibits the best electrochemical performance with initial special discharge capacity of 158mAhg−1 at 0.1C. EIS results demonstrate that the charge transfer resistance of the sample decreases greatly by doping an appropriate amount of Na. [Copyright &y& Elsevier]

Abstract: Cl-doped LiFePO4/C cathode materials were synthesized through a carbothermal reduction route, and the microstructure and electrochemical performances were systematically studied. Cl-doped LiFePO4/C cathode materials presented a high discharge capacity of ∼90mAhg−1 at the rate of 20C (3400mAg−1) at room temperature. Electrochemical impedance spectroscopy and cyclic voltamperometry indicated the optimized electrochemical reaction and Li+ diffusion in the bulk of LiFePO4 due to Cl-doping. The improved Li+ diffusion capability is attributed to the microstructure modification of LiFePO4 via Cl-doping. [Copyright &y& Elsevier]

Abstract: The geometric parameters of 1, 3-benzodioxol-2-one (BO) and propylene carbonate (PC) was optimized at the B3LYP/6-311++G (d, p) level of density functional theory (DFT) with the polarized continuum models (PCM). The obtained frontier molecular orbital energies and vertical electron affinities indicate that BO is reduced more easily than PC. The transition state (TS) of ring-opening reaction BO −1 →BO −1 was optimized and confirmed by vibrational frequency analysis and intrinsic reaction coordinate (IRC) method. The bond orders and atomic charge distribution of the stable points along the minimum energy path (MEP) were analyzed using the natural bond orbital (NBO) method at the B3LYP/6-311++G(d, p) level of DFT. With these calculated results, the reduction mechanism of BO for the formation of solid electrolyte interface (SEI) film on anode of lithium ion battery can be inferred as: BO+e→BO −1 →BO −1 →⋯→SEI Film. [Copyright &y& Elsevier]

Abstract: In this work, a novel composite consisting of nanosized silicon highly dispersed within the porous, elastic and conductive oxide/carbon matrix has been developed as an anode candidate for lithium ion batteries. The composite was prepared by a mechanochemical reaction between SiO and Li under ball milling followed by a carbon coating using the pyrolysis of poly(vinyl chloride)–co-vinyl acetate. The porous structure can effectively suppress the volume change of silicon during the electrochemically Li-alloying process. No obvious capacity fading was observed up to 100 cycles with a stable capacity of 620mAhg−1. The factors influencing the microstructure and the electrochemical behavior of the composite were discussed. [Copyright &y& Elsevier]

Abstract: Composite consisting of nanosized silicon, Li4SiO4 and other lithium-rich components was synthesized using high energy mechanical milling (HEMM) method. The reactive milling of SiO with lithium metal resulted in the oxidation of lithium and silicon, and reduction of SiO. X-ray diffraction (XRD) and high-resolution transmission electron microscope (HRTEM) were used to determine the phases present in the composite. In addition, cyclic voltammetry (CV), along with constant current discharge/charge tests, was used to characterize the electrochemical properties of the resultant material. Compared with pure SiO and pure silicon as anode materials, the as-prepared composite demonstrated larger capacity and superior cyclability even at high C-rate. [Copyright &y& Elsevier]

The incorporation of ultrafine SnO 2 particles inside N-doped ordered mesoporous carbon (N-CMK3) is suggested as a method to prepare an ultrastable anode material for Li-ion batteries. Sn nanoparticles formed by chemical reduction of SnCl 4 inside N-CMK3 pores are spontaneously reoxidised by dissolved oxygen, resulting in the formation of ultrafine SnO 2 inside N-CMK3 pores. This SnO 2 @N-CMK3 exhibits superior capacity, cyclability, and rate capability. Over 100 cycles at a rate of 0.1C, SnO 2 @N-CMK3 maintains a specific capacity of 635 mAh g−1, corresponding to a capacity retention of 86.6%. Over 1000 cycles at the rate of 0.5C, SnO 2 @N-CMK3 can deliver a capacity of 433 mAh g−1. At an ultrahigh rate of 5C, SnO 2 @N-CMK3 still delivers a capacity higher than that of commercial graphite. The full cell, composed of an SnO 2 @N-CMK3 anode, LiCoO 2 cathode, and sacrificial Li electrode, presents excellent performance, better than previous reports of Li-ion cells. By employing a sacrificial Li electrode, the issue related to the low Coulombic efficiency of SnO 2 @N-CMK3 in the first few cycles and the pre-lithiation SnO 2 @N-CMK3 electrode can be successfully addressed. Image 1 • Ultrafine SnO 2 particles are filled inside mesopores of N-CMK3. • SnO 2 @N-CMK3 exhibits the reversible capacity of 635 mAh g−1 at the rate of C/10. • An original three-electrode full cell using SnO 2 @N-CMK3 anode is designed. • Sacrificial Li electrode in the full cell improves coulombic efficiency. • The full cell delivers 608 mAh g−1 with 83.8% retention over 200 cycles. [ABSTRACT FROM AUTHOR]