Physics

Carbonization

Electrode

Organic chemistry

Separator (oil production)

Bacteria

Porosity

Biology

Engineering

Catalysis

Physical chemistry

Specific surface area

Composite material

Chemistry

Materials science

Scanning electron microscope

Cellulose

Bradyrhizobium japonicum

Bacterial cellulose

Rhizobiaceae

Capacitance

Chemical engineering

Symbiosis

Electrochemistry

Genetics

Supercapacitor

Thermodynamics

ACS Sustainable Chemistry & Engineering

Bradyrhizobium japonicum (BJ), which has a symbiotic relationship with soybean roots, possessed an abundant three-dimensional (3D) structure with a high N content. A soybean leaf (SL) with a hierarchically ordered macroporous network and numerous polar hydroxyl groups was proposed as a separator for a supercapacitor. A 3D hierarchical porous carbon was prepared by the facile carbonization with chemical activation of BJ. The as-prepared material possesses a large specific surface area (1275 m2·g–1), unique 3D hierarchical porosity, and good electrical conductivity. The electrochemical performance of the Bradyrhizobium japonicum-derived porous carbons at a mass ratio of 1.5 (ZnCl2/BJ = 1.5) (BJPC-1.5) for supercapacitors with a SL separator showed a high capacitance (358 F/g at 1 A·g–1), a superior cycle stability of 91% over 8000 cycles, and a superior rate capability in a symmetric two-electrode supercapacitor in 6 M KOH. Furthermore, the electrochemical performance of the BJPC-1.5 with a SL separator was comparable to that with the commercialized cellulose and polypropylene (PP) separators. More attractively, the SL separator with a preferable water uptake showed a much better performance in the BJPC-1.5 cell than the PP separator. These results provide an insight into the full usage of a natural and biodegradable biomass for separator and electrode materials for a supercapacitor.

One Step Construction of Nitrogen–Carbon Derived from <i>Bradyrhizobium japonicum</i> for Supercapacitor Applications with a Soybean Leaf as a Separator

One Step Construction of Nitrogen–Carbon Derived from Bradyrhizobium japonicum for Supercapacitor Applications with a Soybean Leaf as a Separator