Biowaste-Derived Three-Dimensional Porous Network Carbon and Bioseparator for High-Performance Asymmetric Supercapacitor

Abstract

To explore renewable resources and reduce pollution, the common biowaste eggshell membrane (ESM) is utilized for electrode materials and separators in asymmetric supercapacitor. This device includes air-activated ESM carbon as the negative electrode, MnO 2 nanoparticle/chemicalactivated ESM carbon as the positive electrode, and natural ESM as the separator, achieving a high energy density of 14 W h kg −1 along with acceptable power density of 150 W kg −1 and cycling stability (79% capacitance retention after 1000 cycles). Significantly, the air-activated ESM carbon achieves a superior specific capacitance of 478.5 F g −1 in 1.0 M Na 2 SO 4 , and the natural ESM based bioseparator displays an impressive ion conductivity and cycling stability. This work demonstrates an operable way to reuse the common biowaste for renewable energy devices with high performance.

Coaxial Cable‐Like Carbon Nanotubes‐Based Active Fibers for Highly Capacitive and Stable Supercapacitor

“…This gradual decrease is attributed to the phenomenon that diffusion limits the movement of ions with time constraint. [ 40 ] Energy density and power density are two critical factors for evaluating the practicability of supercapacitor devices. [ 41 ] Ragone plot of the fabricated symmetric CNT/PMo/PANI supercapacitor is shown in Figure 6b.…”

Advances in materials and fabrication of separators in supercapacitors

“…In another such attempt, bio-waste ESMs were used for the development of electrodes and separator in the design of asymmetric SCs. 111 Biomaterials when carbonized, oxygen and nitrogen can firmly be doped in the carbon structure. Such bio-derived carbon does not only offer optimum pore size (size bigger than microporous structure) for ion absorption/transport but also the additional pseudo-capacitance due to presence of O and N. 112,113 The combination of air-activated ESM carbon as cathode, MnO 2 nanoparticles-chemically activated ESM carbon as anode, and natural ESM bio-separator displayed good electrochemical performance (Table 3) and showed a path for making renewable energy devices by utilizing the biowaste materials.…”

Adapting a Kinetics-Enhanced Carbon Nanostructure to Li/Na Hybrid Water-in-Salt Electrolyte for High-Energy Aqueous Supercapacitors

“…Considering the environmental deterioration and energy crisis, it is highly desirable to develop high-efficiency and sustainable energy storage/delivery systems. , Carbon-based supercapacitors, as a burgeoning energy storage device, are currently coming into the spotlight because of their fast charge/discharge capability, superior power output, and long service life. − Since energy storage E is proportional to the square of the potential V in the formula E = 1/2 CV 2 ( C , capacitance), emerging wide-potential electrolyte systems are widely reported to upgrade the low-energy bottleneck caused by the finite working potential window of conventional aqueous supercapacitors at 1.23 V. , These reported devices generally employ commercial activated carbons (ACs) as the electrode materials, but there still exists significant disadvantages affecting the electrode/device capacitance C as follows: (1) hydrophobic carbon surface and weeny-sized pores (<0.5 nm) result in the under-utilization of ample electrode surface (>3000 m 2 g –1 ) toward large wide-potential electrolyte ions, and manifested interfacial charge accumulation is blocked for generating electrical double interlayers ,− and (2) tortuous/island-like pore structures cannot efficiently transfer viscous concentrated media owing to the boosted mass transportation resistance and electrolyte penetration pathway, simultaneously kinetically sacrificing energy/power supply. ,,, Hence, for better adaption to progressive wide-potential electrolytes, the ingenious design of high-capacity carbon electrodes with structurally interconnected channels and highly accessible surface area is a challenging and valuable ongoing task towards advanced supercapacitors.…”