摘要 |
A secondary lithium cell in which the anode is made by first taking an electrode comprising a material which undergoes a structural change when it is first charged and discharged such as a layer of tin, assembling a cell comprising the said anode, a cathode containing lithium ions, and an electrolyte containing lithium ions, passing an electric current through the cell so as to insert lithium ions into the material e.g. tin and so charge the cell, and then discharging the cell. This cell is then dismantled, and the anode removed and any electrolyte washed off. The layer of tin or other material is then coated with a layer comprising a polymeric material. This coated and pre-cycled electrode can then be used as an anode in a secondary lithium cell. The polymeric coating, which may be a microporous polymer, a plasticised polymer, as gel polymer, or a polymeric electrolyte, for example based on polyvinylidene fluoride, suppresses the deterioration in cell performance on subsequent cycling. |