Layered SnS2-reduced graphene oxide composite--a high-capacity, high-rate, and long-cycle life sodium-ion battery anode material.

A layered SnS -reduced graphene oxide (SnS -RGO) composite is prepared by a facile hydrothermal route and evaluated as an anode material for sodium-ion batteries (NIBs). The measured electrochemical properties are a high charge specific capacity (630 mAh g at 0.2 A g ) coupled to a good rate performance (544 mAh g at 2 A g ) and long cycle-life (500 mAh g at 1 A g for 400 cycles). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. 2 2 -1 -1 -1 -1 -1 -

Engineering oxygen vacancies in hierarchically Li-rich layered oxide porous microspheres for high-rate lithium ion battery cathode

Abstract(#br)Lithium-rich layered oxides always suffer from low initial Coulombic efficiency, poor rate capability and rapid voltage fading. Herein, engineering oxygen vacancies in hierarchically Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 porous microspheres (L@S) is carried out to suppress the formation of irreversible Li 2 O during the initial discharge process and improve the Li + diffusion kinetics and structural stability of the cathode mateiral. As a result, the prepared L@S cathode delivers high initial Coulombic efficiency of 92.3% and large specific capacity of 292.6 mA h g −1 at 0.1 C. More importantly, a large reversible capacity of 222 mA h g −1 with a capacity retention of 95.7% can be obtained after 100 cycles at 10 C. Even cycled at ultrahigh rate of 20 C, the L@S cathode can..

A three-dimensional network of graphene/silicon/graphene sandwich sheets as anode for Li-ion battery

Abstract(#br)A freestanding porous three-dimensional (3D) network composed of graphene/silicon/graphene sandwich sheets is proposed to prevent the expansion induced pulverization for Si-based anode in a lithium-ion battery. The architecture ensures the attachment of Si active material, improves the conductivity, and absorbs the Si volume expansions. The 3D Graphene and Si in this architecture work synergistically to contribute to the capacity, while the nanoscale of Si lowers the expansion during lithiation. And the 3D graphene with an interconnected skeleton, in addition to active material, also acts as the current collector as well as a stable support for Si

Surface Ni-rich engineering towards highly stable Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 cathode materials

Abstract(#br)Li-rich layered oxide cathode materials (LLOs) are regarded as promising next-generation cathode candidate in high-energy-density lithium ion batteries due to their high specific capacity over 250 mA h g −1 . However, LLOs always suffer from a series of severe issues, such as rapid voltage fading, fast capacity decay and bad cycling stability. In this work, Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 -Li 1.2 Mn 0.44 Ni 0.32 Co 0.04 O 2 (LLO-111@111/811) hybrid layered-layered cathode is constructed via facilely increasing surface Ni content. Profiting from this special design, the prepared LLO-111@111/811 cathode exhibits a remarkable specific capacity of 249 mA h g −1 with a high capacity retention of 89.3% and a high discharge voltage of 3.57 V with a voltage retention of 83.0% after cycling 350 times at 0.5 C. As a result, the specific energy of LLO-111@111/811 cathode is 887 Wh Kg −1 at 0.5 C and it keeps as high as 658 Wh Kg −1 after 350 cycles. LLO-111@111/811 also exhibits an initial high capacity of 169 mA h g −1 at a high rate of 5 C and maintains a good capacity retention of 90.0% after 200 cycles. This strategy can successfully improve structural stability, suppress capacity decay and restrain voltage fading of LLOs, which is beneficial for their practical application

Comparison of the electrochemical performance of iron hexacyanoferrate with high and low quality as cathode materials for aqueous sodium-ion batteries

High quality iron hexacyanoferrate nanocubes (HQ-PB NCs) were synthesized, which exhibited excellent electrochemical performance as cathode materials for aqueous sodium-ion batteries.</p