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Hierarchical ultrathin NiCo 2 O 4 nanosheeets grown on uniform hollow carbon microspheres (HC@NiCo 2 O 4 ) are designed and fabricated by a solvothermal reaction followed with an annealing process. When evaluated as an anode for lithium ion batteries, the as-prepared HC@NiCo 2 O 4 microspheres exhibit excellent electrochemical performance (a high reversible capacity of 1015 mA h g −1 after 100 cycles at a current density of 0.1 A g −1 and a high capacity of 805 mA h g −1 even at a high current density of 0.5 A g −1 ). By pairing with the LiCoO 2 cathode, the HC@NiCo 2 O 4 anode also manifests excellent performance in full cells. The outstanding electrochemical performance in half and full cells can be attributed to its unique structure, which can not only promote the contact of electrode and electrolyte during the charge and discharge processes, but also shorten the transmission path of electrons and ions. More importantly, this study inspires a better design of various metal oxide/carbon electrode materials for high performance lithium ion batteries. [ABSTRACT FROM AUTHOR]

In this study, we develop a simple template-free strategy to fabricate uniform porous CuCoO hollow spheres. The shells of the as-synthesized CuCoO hierarchical hollow nanostructures are composed of primary nanoparticle units, leading to a superior specific surface area of 51 m g. When applied in lithium ion batteries, the porous CuCoO hollow spheres show excellent lithium storage performance, which could deliver a high specific capacity of 930 mAh g after 150 cycles for half-cell and 660 mAh g after 50 cycles for full cell. The good electrochemical properties of the as-synthesized porous CuCoO hollow spheres can be attributed to their unique porous structure, which is beneficial for shorting lithium ion-electron transmission path and alleviating the structural strain of volume change. [ABSTRACT FROM AUTHOR]

Abstract: A hybrid material of carbon-coated Fe2O3 submicro-particles loaded on graphene nanosheets (Fe2O3@C/GNs) is prepared by a two step route including a hydrothermal and a subsequent glucose impregnation-pyrolysis process. The obtained material is composed of GNs and ∼400 nm size Fe2O3 particles coated by thin carbon layer with a thickness of 5 nm. As an anode material for lithium ion batteries, Fe2O3@C/GNs hybrid shows an improved electrochemical performance in the initial coulombic efficiency (71%), reversible capacity (900 mA h g−1 after 50 cycles at a current of 200 mA g−1) and capacity retention rate (82% after 50 cycles). This result is much better than the synthesized bare Fe2O3 and Fe2O3/GNs electrodes. In addition to the contribution of GNs, the carbon-coated layer around Fe2O3 particles is believed to be a key factor to improve the electrochemical performance of Fe2O3. [Copyright &y& Elsevier]

The flexible electrode material of SnO 2 /carbon cloth (SnO 2 /CC) is fabricated by RF magnetron sputtering method. As an anode material of lithium ion batteries, the SnO 2 /CC electrode exhibits more excellent cycling stability and rate capability than that of the pure carbon cloth and SnO 2 . The reversible capacity always maintain about 1.98 mAh/cm 2 during 50 cycles, which is higher than that of the pure CC (about 1.61 mAh/cm 2 ) and SnO 2 (about 0.08 mAh/cm 2 ). After 100 cycles, the capacity of SnO 2 /CC sample is 1.85 mAh/cm 2 , still retaining 89.4% of the initial capacity. The good electrochemical properties of SnO 2 /CC are mainly caused by the high surface area, porous structure and the intrinsic soft characteristics of CC, which can effectively accommodate the volume charge during charge and discharge process. [ABSTRACT FROM AUTHOR]