Energy storage


Tabby graphene has proved to be valuable for the development of anodes in rechargeable post-lithium batteries.

The latter might lead to quick implementation in industry. The investigation of alternatives to lithium is highly desirable. The bulk of world lithium reserves are found in politically sensitive regions: Bolivia 42%; Chili 23%, Argentina 16%, China 9%,Brasil 7%, and US 3%. Li batteries are hazardous:   A relatively small fire source is sufficient to start a lithium battery fire. A U.N. panel (USA) approved on 22.02.2016 a temporary ban on shipments of rechargeable lithium batteries on passenger planes because they can create intense fires capable of destroying an aircraft.

Sodium batteries are more stable when discharged to lower potentials and thus show better safety characteristics. Mg and Al are able to deliver more than one charge per atom: higher energy storage capabilities. Mg, divalent and denser, is theoretically capable of delivering highest volumetric energy density; it is 24 times less expensive than Li, and it is quite safe to handle. Aluminum batteries attracted attention due to high theoretical voltages and specific energy, low flammability and low cost. Main problem is the size: only Li can intercalate graphite. Tabby has an increased interlayer distance and can accommodate Na, Mg, Al. Our preliminary results show that graphene derivatives are very promising in this field.

Two few-layer graphene materials, strongly distinguished in structure, were compared as electrode materials for supercapacitor. Electrochemical testing of the graphene materials detected re-stacking of thin crumpled layers during the electrode preparation. Furthermore, graphene material produced from the fluorinated graphite showed poor wettability. The mild oxidation of the material in a mixture of sulfuric and nitric acids allowed increasing the capacitance in several times.