Materials of Tin-Based Negative Electrode of Lithium-Ion Battery

Among high-capacity materials for the negative electrode of a lithium-ion battery, Sn stands out due to a high theoretical specific capacity of 994 mA h/g and the presence of a low-potential discharge plateau. However, a significant increase in volume during the intercalation of lithium into tin leads to degradation and a serious decrease in capacity. An efficient method to overcome this drawback is to create composites with nickel or carbon to prevent the occurrence of microstresses. Powders of Sn-Ni samples were produced by the reduction of metals in the liquid phase and analyzed by X-ray powder diffraction analysis. A Sn/carbon nanotubes powder was obtained by heat treatment in a vacuum and studied by scanning electron microscopy. The electrochemical properties of the material were investigated by chronopotentiometry in a three-electrode electrochemical cell. The Sn/carbon nanotube composite material has a much higher capacity than tin nanopowders when cycling at a current density of similar to 0.1 A/g. It follows from this that the former has better electrochemical properties and can be used as a negative electrode material.