| Although graphite as anode material has been successfully applied in the commercial LIBs,the lower theoretical capacity of 372 mAh g-1 as well as the safety issue of graphite still greatly hampered the further applications of LIBs.With the progress of science and technological innovation,the requirements of anode material are also increasing.Thus,developing novel anode materials with low cost and high performance has become the major challenge of the next generation of LIBs.This work research and development several novel anode materials,the structure of the materials was investigated by X-ray diffraction,scanning electron microscope,transmission electron microscope and the electrochemical performance was mainly studied by using cyclic voltammetry,electrochemical impedance spectroscopy and charge-discharge tests.The main experiments as follows:(1)For the first time,the purchased KMnO4 was directly employed as anode material for LIBs,showing a discharge capacity of 82 mAh g-1 after 20 cycles at the current density of 100 mA g-1.This result meant that a novel materials was found and may reduce the cost of the anode material.Three proportion of graphene-doped KMnO4 were produced by a very simple method of milling,and the significantly enhanced electrochemical performances were exhibited by the graphene-doped KMnO4 as compared to the pure KMnO4.Additionally,a K+and Li+involved mechanism of lithiation and delithiation process was proposed which may roughly explain the electrochemical performance shown by the prepared samples,basing on the CV curves obtained.It is believed that the novel results presented in this preliminary work will have a huge impact on the development of anode material of LIBs.(2)On the basis of the previous work,for the first time,a novel finding,that the 100℃-dried mixtures having KMnO4 and SnCl4 can be employed as anode materials for lithium ion batteries(LIBs),was reported in this work.In the present work,four samples with various Mn to Sn atomic ratios were prepared and investigated systematically.Results of electrochemical measurements demonstrated that when the atomic ratio of Mn to Sn was 1:2,the best electrochemical performance was exhibited by the composite,delivering an initial discharge capacity of 220 mAh g-1 at 100 mA g-1 after 20 cycles.(3)In this work,SnCl4,silicon wafer and graphene were prepared by using a very simple method of an air condition calcination methodas the starting materials.Results of electrochemical measurements demonstrated that the composite delivering an initial discharge capacity of 350 mAh g-1 at 100 mA g-1 after 20 cycles.And a novel structure,namely,core-shell and sandwich structure,was proposed to explain the satisfactory electrochemical performance displayed by sample.It should be emphasized that the preparation process was simple and low cost.Which was very meaningful to the commercial production of LIBs anode materials.(4)For the first time,a novel finding,that the calcined weathered stones can be employed as anode materials for LIBs.XRD and EDS analysis revealed that the main component of both the calcined weathered stone and the pure weathered stone was SiO2.Also,it was demonstrated that the calcination temperature played a key role in influencing the electrochemical behavior of the produced samples,and 600℃-calcined weathered stone showed the best electrochemical performance among all the prepared samples,namely,the discharge capacity of sample was close to 70 mAh g-1 after 20 cycles at a current density of 100 mA g-1.This novel founding has opened a new field regarding the anode materials of LIBs,which was very beneficial to the further commercialization of LIBs. |
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