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We demonstrate a simple and green approach for the synthesis of one kind of anatase TiO 2 nanosheets. The method is based on a hydrothermal method under normal atmosphere without using the complex Teflon-lined autoclave, high concentrations NaOH solution and long reaction time. The as-prepared materials are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) and electrochemical measurements. The obtained anatase TiO 2 nanosheets show excellent performance. There is one pair of potential plateaus at 1.7 and 1.9 V in the process of Li insertion and extraction, and the initial Li insertion/extraction capacities are 382 and 326 mA h g −1 at the current density of 20 mA g −1 , respectively. After 50 cycles, the TiO 2 retains 93% of the initial charge capacity at the current density of 400 mA g −1 . [ABSTRACT FROM AUTHOR]

Abstract: We demonstrate a simple, improved and novel approach for the synthesis of a kind of anatase TiO2 nanosheets and Li4Ti5O12 anode material with excellent electrochemical performance from the natural ilmenite. We use the H2O2 to leach the Ti from the hydrolyzed titania residue under alkaline condition of leaching. Before boiling, the LiOH was added into the leach solution. The obtained precipitation of titanium dioxide hydrate can be purified and refined into special nanostructure by the addition of LiOH. SEM and XRD show that the as-prepared TiO2 are special nanostructure and well-crystallized anatase phase. The analysis of elemental contents reveals that the content percent of TiO2 in as-prepared TiO2 nanosheets is more than 99%. Moreover, the titanium dioxide hydrate can be used to prepare Li4Ti5O12 anode material directly. The obtained Li4Ti5O12 shows charge specific capacities of 161,138 and 113mAhg−1 at 0.1C, 0.5C and 1C rates, respectively, and excellent cycling stability. [Copyright &y& Elsevier]

Abstract: Spinel Li4Ti5O12 anode material is successfully synthesized by a solid-state method using lithium carbonate and titanium precursors which are prepared by the low cost industrial titanyl sulfate solution. The characters of H2TiO3 and TiO2 precursors are determined by TG/DTA and SEM methods. TG-DAT and EDS methods show that H2TiO3 can absorb sulphate ions which can be present as impurities. XRD method shows that the impure phases of Li2SO4 and rutile TiO2 appear in Li4Ti5O12 synthesized by H2TiO3. The formation of Li2SO4 is identified in thermodynamics during the process of calcination. Owing to the formation of Li2SO4 impurity, the capacity of the Li4Ti5O12 synthesized by H2TiO3 is low. One effective way that can tackle this problem is to remove the sulphur by calcining H2TiO3, after calcinations, the production will have a thermal treatment with Li2CO3. The obtained Li4Ti5O12 shows better electrochemical performance. The specific capacities can be increased by 20mAhg−1 at 0.1, 0.5 and 1C rates. [ABSTRACT FROM AUTHOR]

Sodium‐metal batteries, with high energy density and low cost, are emerging stars in the field of large‐scale energy storage and power batteries. The application of sodium metal is hindered by side reactions between the active sodium metal anode and the electrolyte, unstable solid electrolyte interphase, and dendrite growth caused by the uneven distribution of sodium ions. Here, heterogeneous interface layer composed of the sodium fluoride and metallic cobalt (NaF/Co) is constructed in situ and spontaneously by introducing the CoF2 nanoparticles confined in carbon to the Na metal surface. The NaF/Co artificial interface layer with high Young's modulus, high Na+ conductivity, high surface energy, and strong sodiophilicity renders the Na+ evenly distributed, suppresses Na‐dendrite growth, and reduces side reaction with electrolyte. Due to these virtues, the Na||Na symmetric cells with NaF/Co interface layers demonstrate long cycle life (1000 h at 1.0 mA cm−2, 1.0 mAh cm−2). Moreover, when the NaF/Co/Na anode is matched with Na3V2(PO4)3 cathode, the produced full battery (Na3V2(PO4)3||NaF/Co/Na) exhibits a long lifespan of 1000 cycles at 15 C and a high‐rate capacity of ≈52 mAh g−1 at 60 C. This work provides a new strategy to solve the dendrite growth of Na metal anodes. [ABSTRACT FROM AUTHOR]

[Display omitted] As alloying-type anode materials, metallic aluminum owns an ultra-high specific capacity (993 mAh g A l - 1 to LiAl) for Li storage, which is low-cost and a promising candidate for next-generation rechargeable batteries with high energy densities. However, metallic Al anodes suffer from irreversible lithiation of naturally occurring alumina layer during cycles, resulting in rapid capacity decay of Al anode-based batteries. Herein, Li supplement nucleated on Al foil via a controllably electrochemical pre-lithiation technology is employed for achieving high-performance elemental foil anodes. In full batteries, the pre-lithiated areas continuously supply Li outward during dealloying process to compensate for irreversible lithium loss during alloying process that preferentially alloys the unreacted Al 2 O 3 surface layer along the rolling direction of Al foil until the entire surface is covered by Li x AlO y. This lithiation behavior can avoid the severe stress concentration during alloying to prevent the perforation and pulverization of foil, making commercial Al foil succeed as single-material anodes. The produced commercial Al foil anode-based Li-ion batteries employing various commercial cathodes demonstrate promising electrochemical performances. For example, the Al||LiNi 0.8 Co 0.1 Mn 0.1 O 2 battery offers a high specific capacity of 180 mAh g−1, an excellent capacity retention of ∼90% after 400 cycles, and relatively stable solid electrolyte interface without any dendrite. [ABSTRACT FROM AUTHOR]

Abstract: Using nano-Si, glucose and flake graphite of ∼0.5μm as raw materials, flake graphite/silicon/carbon composite is successfully synthesized via spray drying and subsequent pyrolysis. The samples are characterized by XRD, SEM, TEM and electrochemical measurements. The composite is composed of flake graphite, nano-Si and amorphous glucose-pyrolyzed carbon and presents good spherical appearance. Some micron pores arising from the decomposition of glucose exist on the surface of the composite particles. The composite has a high reversible capacity of 602.7mAh/g with an initial coulombic efficiency of 69.71%, and shows nearly the same cycleability as the commercial graphite in 20 cycles. Both the glucose-pyrolyzed carbon and the micron pores play important roles in improving the cycleability of the composite. The flake graphite/silicon/carbon composite electrode is a potential alternative to graphite for high energy-density lithium ion batteries. [Copyright &y& Elsevier]

Abstract: Titanium-containing precursor is prepared from the high-titanium residue, which is obtained from the ilmenite by a mechanical activation and leaching process. After two-step alkaline leaching, about 95% of silicon dioxide is separated from the high-titanium residue. The purified titanium-containing precursor is used to synthesize Li4Ti5O12. XRD shows that the synthesized Li4Ti5O12 is cubic spinel phase and well crystallized. At the discharge-charge rate of 0.1C and 0.5C, its discharge capacities are 138.3 and 126.8 mAh/g, respectively. [ABSTRACT FROM AUTHOR]

Abstract: The electrode films fabricated with the Lithium titanate powders have been surface modified with metallic copper by electroplating process. The electrochemical performance of the pristine and copper coated anodes has been investigated by Galvanostatic cell cycling and AC impedance spectroscopy. The copper coated anodes exhibit improved rate capability and cycling performance than those of the pristine anode. An analysis of the charge–discharge capacity values and electrochemical impedance spectroscopy (EIS) measurements reveals that the improved electrochemical performances of the copper coated sample are due to the enhancement of charge transfer reaction. [Copyright &y& Elsevier]

• Introducing oxygen into Sn and carbon paper composite framework improves the wettability to molten Li. • The formed Li-Sn alloy has outstanding Lithiophilicity and Li 2 O can homogenize Li+ flux. • The prepared electrode can operate without dendrite growth or volume expansion. • Ultra-low voltage hysteresis (16 mV) is enabled for 800 h in symmetric cells. The uncontrollable dendrite formation and infinite volume expansion bring serious safety risks and short service life to high-energy lithium (Li) metal batteries. Here, by introducing oxygen as a type of SnO 2 into the Sn and carbon paper (CP) composite, a lithiophilic framework (CP/Sn/SnO 2) is proposed as Li storage host for stable Li metal anode. It demonstrates that the wettability of the framework to Li can be greatly improved by partial oxidation of Sn. Then, the spontaneous reaction between the formed SnO 2 and molten Li can induce the alloying of Li and Sn. Consequently, both of Sn and SnO 2 in the framework finally converse to lithiophilic Li-Sn alloy as well as a small amount of lithium conductor Li 2 O. After molten Li injection, the prepared CP/Sn/SnO 2 @Li electrode achieves a dendrite-free morphology, near-zero volume change and extraordinary electrochemical performance. Furthermore, low interfacial resistance and long-term lifetime for 800 h at 1 mA cm−1 with an ultra-low voltage hysteresis of 16 mV in symmetric cells and excellent cycling stability in full cells with LiFePO 4 cathode are realized. The oxygen-induced strategy provides important advancement for a stable 3D lithiophilic framework with low Li 2 O content in developing safe and commercial Li metal batteries. [ABSTRACT FROM AUTHOR]