Assessment of ecologically prepared carbon-nano-spheres for fabrication of flexible and durable supercell devices

We report the production parameters of single-stage, ecologically fabricated, flexible Carbon-Nano-Spheres (CNS) supercells. These supercells can deliver a total energy, E-D, of 100.0 W h kg(-1) and power density, P-D, of 50.0 W kg(-1)@38.4 V and 20 mA for a payload of 15 g (5.0 x 2.5 cm(2)). According to the material analysis, CNS consists of a spherically (40.0 to 50.0 nm) coagulated, interconnected, 3D network of hetero-structured sp(2)/sp(3) carbon with a low crystalline length, L-a, of similar to 3.0 nm and containing a native O-moiety (12.0 at%). They have an appreciably high specific surface area, S-A, of similar to 790.0 m(2) g(-1) and an average pore size of similar to 3.42 nm combined with multi-channel pore size distribution. Upon integration in electrodes, CNS provided excellent electrochemical performance without any material modification. CNS showed a nearly rectangular cyclic voltammetry (CV) response in 1 M HCl for both two-and three-electrode systems, yielding superior specific capacitances, C-SP, of similar to 1080.0 and 570.0 F g(-1), respectively (@10 mV s(-1)). They maintained a high cyclic stability of similar to 86.0% (@ 20 000 cycles), with no material degradation according to post-investigations at a molecular level. The electrode showed hybrid battery/electric double layer capacitor (EDLC) behavior, as revealed by Ragone studies. In Nyquist studies, a shift in the Knee frequency with cycling indicated mitigation of the charge transfer process. In Bode studies, the ionic phase shift decreased insignificantly from similar to 80 degrees to similar to 77 degrees after 1000 cycles. The performance characteristics of CNS from laboratory scale measurements to supercell-level device development are discussed.