| 摘要 |
PURPOSE:To keep electromotive force constant by changing electrode film components in the direction of film thickness. CONSTITUTION:The film components of an alloy electrode 204 are changed in the direction of film thickness in consideration with the change in the electrode surface condition attendant on discharge. For example, when lithium and aluminium are sputtered on a current collector 201, the revolution speed of a motor 22 is changed with sputtering time to change the holding time of the current collector 201 on a lithium target 20 and an aluminium target 21. In the initial stage of sputtering, the holding time of the current collector 201 on the lithium target 20 is lengthened and that on the aluminium target 21 is lengthened with time elapsed to form a lithium-aluminium alloy electrode 204 in which aluminium concentration is gradually decreased from the surface. The electromotive force of a storage battery is kept constant over the period of use without drop in energy efficiency. |
