Li-ion battery electrode property of functional molecules encapsulated in single-walled carbon nanotubes

摘要

Here, we report on new generation secondary batteries using functional molecules encapsulated in single-walled carbon nanotubes as electrode active materials. Li-ion battery (LIB) whose energy density is the highest among the secondary batteries has been widely used for cell phones, notebook computers and so on. Recently it has become to be used for electric vehicles including plug-in hybrid cars. However, it should be noted that LIB is facing today serious problems related to safety concerns and resource costs. The latter problem is caused partly by the use of what we call "rare metals" in the cathode active materials such as LiCoCh and LiNiO2. Organic electrode active materials are expected for the replacement of the expensive rare metal oxides. However, it is generally very difficult for LIB using the organic electrode active materials to show good cyclability because organic materials tend to dissolve in the electrolyte during charge-discharge cycles. If the dissolution can be restricted, we could obtain cheap and flexible LIBs. For that purpose we tried to use organic electrode active materials encapsulated in single-walled carbon nanotubes. Here, we show the electrode property of anthraquinone molecules encapsulated in SWCNTs.