A sustainable route from biomass byproduct okara as a natural nitrogen fertilizer to high content N-doped carbon sheets is demonstrated. The as-prepared unique structure exhibits high specific capacity (292 mAh g^-1) and extremely long cycle life (exceeding 2000 cycles). A full battery is devised for the practical use of materials with a flexible/wearable LED screen.

http://onlinelibrary.wiley.com/doi/10.1002/adma.201503221/full#rd