Supercapacitor thread concept art (via Peking University)
Researchers from Peking University in China have discovered a novel way to increase a flexible carbon-based supercapacitors performance "tenfold" over typical supercapacitors using simple pen ink. The electric double-layer capacitor (EDLC) has a rather high energy density over common electrolytic capacitors (around a hundred times greater) and has a greater rate at charging and discharging electrical energy. Most of today’s supercapacitors are made using carbon to carbon (activated carbon) electrodes, metal-oxide electrodes or in recent developments the use graphene to achieve the high electrical density, but they have a high manufacturing costs as a result of using those materials.
This is where the Peking University research team’s new design shines. Their supercapacitor uses pen ink, which can cut the manufacturing costs but also enable the capacitor to be bent into a complete circle. Their design uses a pair of carbon-fiber electrodes that are individually covered in pen ink (more on this in a minute), which is then rapped with a helical spacer wire and encased in electrolyte-filled plastic tube (1mm in diameter). The secret to their supercapacitor lies with the readily available commercial pen ink for the capacitors electrochemical material. The team found that most regular pen ink contains carbon nano-particles that has the same properties as those previously mentioned but can also cover a large surface area (27 square meters from 1 gram) while achieving a greater capacity (10X more) at holding a charge. The team states that their supercapacitor design could be weaved with other fibers to create ‘wearable electronics’ or incorporated into future mobile devices, which would give a new meaning to the term ‘talking on the run’.
Cabe
