Sn/SnO Anode Materials Prepared By Platinganodizing And Its Properties

Because of high energy density, high power density, good safety performance, long life cycle, and low pollution, lithium-ion batteries are used as an ideal power storage device. The anode material has a significant impact on specific capacity and cyclability as an important part of lithium-ion batteries. Graphite is the commonly used as the anode material with a theoretical specific capacity of 372 mAh g-1. So far, the specific capacity of carbon anode material has been close to the theoretical specific capacity, so it is unlikely to further improve the lithium storge properties.Tin oxide(TO)is a very promising high performance anode material. Its theoretical specific capacity is 990 mAhg-1 almost three times that of carbon materials, attracting the extensive attention of scientists from all over the world. Though the first discharge capacity of these anode materials is high, TO suffers from severe capacity fading during cycling because of the large volume deformation during the charge-discharge process.Because of these problems, this paper choosed Sn-based lithium-ion battery anode materials as research objects. In order to control the morphology, structure and composition of this material, amorphous nanoporous stannous oxide(ANSO) composite with carbon nanotubes(CNTs) electrode material is synthesized by electrodeposition and anodic oxidation methods. These materials were characterized by XRD, SEM, TEM, and BET. Their electrochemical performances have been evaluated by galvanostatic method, electrochemical impedance spectroscopy, cyclic voltammetry(CV) and galvanostatic charge-discharge tests. This dissertation has made innovative achievements, such as:(1) TO thin film anode material was synthesized by electrodeposition and anodic oxidation methods used copper foil as current collector. The surface morphology of the oxidation films are different when using different electrolyte. We synthesized amorphous nanoporous stannous oxide(ANSO) electrode material use 0.1M oxalic acid solution as electrolyte with constant potential of 8 V. The first discharge capacity of this electrode material is as high as 905.4mAhg-1. After 50 charge-discharge cycles the capacity is maintained at 513 mAhg-1.(2) In order to obtain more preferable tin oxide thin film negative electrode material, we composite ANSO with CNTs. The amorphous nanoporous stannous oxide(ANSO) composite with carbon nanotubes(CNTs) electrode material is synthesized by composite plating and anodic oxidation methods. The ANSO/CNTs electrode material as an anode material for lithium-ion batteries exhibits a highly reversible specific capacity, stable cycling ability and good rate capabilities. The first discharge capacity of this electrode material is as high as 1895 mAhg-1. After 50 charge-discharge cycles the capacity is maintained at 926 mAhg-1.(3) Use nickel foam as the base material to replace copper, use 0.5A/dm2 constant current to electrodeposited tin precursor obtained, still use 0.1M oxalic acid solution at a constant voltage of 8V to anodize the precursor.The prepared stannous oxide particles uniformly distributed on the nickel foam. The initial capacity of the electrode material is 837 mAhg-1, after 39 charge-discharge cycles the capacity there are still 306.5 mAhg-1.