Design and synthesis of high performance flexible and green supercapacitors made of manganese‐dioxide‐decorated alkali lignin

Abstract

State-of-the-art flexible supercapacitors suffer from electrochemical and environmental performance issues including manufacturing expense limitations. Therefore, a highly effective and low-cost strategy to develop supercapacitors is needed. To address this, a plant-based, high-performance, lightweight, lowcost, quasi-solid state, and composite electrode for flexible supercapacitors has been synthesized using the hydrothermal method. The composite electrode is made of alkali lignin and is decorated with MnO 2 particles including an Al substrate. An Al/lig/MnO 2 based anode and an Al/AC (activated carbon) based cathode were sandwiched using an inorganic polymer gel-type electrolyte made of PVA/H 3 PO 4 in order to assemble the supercapacitor. Synchrotron tomography and SEM are employed to study the detailed electrode morphology. Electrochemical impedance spectroscopy (EIS), cyclic charge-discharge (CCD), and cyclic voltammetry (CV) have been used to assess electrochemical performance. Optimization is carried out using a series of lignin:MnO 2 samples with varying constituent ratios. After 3000 charge-discharge cycles, the highest specific capacitance value achieved at 40 mA g −1 reached 379 mF cm −2 , (900 times reported). The capacitance retention, maximum energy density, and maximum power density are 80%, 6 Wh kg −1 , and 355 W kg −1 respectively. Due to the superior electrochemical performance, the supercapacitor shows exceptional potential for future sustainable and green electronics.

Lignin-Derived Quinone Redox Moieties for Bio-Based Supercapacitors

“…The ability to attain relatively high pseudocapacitive performance, arising from their many valence state transitions, is key to their electrochemical characteristics [ 59 ]. Combining lignin with metal oxides can improve the electrochemical characteristics of electrodes [ 60 , 61 , 62 , 63 , 64 ]. Incorporating lignin into metal oxides for supercapacitor applications has proven challenging, due to difficulties in regulating the resulting electrochemical properties, with significant impacts on the cycle life and performance of the devices.…”

“…Jha et al used a similar approach to fabricate Al/lignin/MnO 2 –based anodes for supercapacitors [ 61 ]. They decorated alkali lignin with MnO 2 particles and then coated it onto an Al substrate to make the composite electrode.…”

Diffusion kinetics of CuCo2O4 nanorods for next‐generation solid state sodium‐ion hybrid supercapacitor

“…Many transition metal-based oxides (TMOs), including Fe 2 O 3 , NiO, Ru 2 O, Co 3 O 4 , ZnO, and MnO 2 , have been described as the cathode (battery-like) materials for HSCs owing to their reasonable cost high theoretical capacitance, layered structure, and capacity to embed multiple oxidation states that are responsible for rapid faradic redox reactions. [9][10][11][12] Despite the fact that HSCs show excellent growth but they are plagued by a number of challenges, including low cycle performance, small range of cell potential and a lack of accessible anode/cathode electrode materials. 13 Therefore, there is great potential to enhance the performance of HSCs by employing superior electrode materials and polymer gel electrolytes.…”

“…The battery‐type electrode‘s ability to store energy is achieved entirely through faradic processes, and the ion diffusion process has a substantial impact on the electrochemical performance. Many transition metal‐based oxides (TMOs), including Fe 2 O 3 , NiO, Ru 2 O, Co 3 O 4 , ZnO, and MnO 2 , have been described as the cathode (battery‐like) materials for HSCs owing to their reasonable cost high theoretical capacitance, layered structure, and capacity to embed multiple oxidation states that are responsible for rapid faradic redox reactions 9‐12 . Despite the fact that HSCs show excellent growth but they are plagued by a number of challenges, including low cycle performance, small range of cell potential and a lack of accessible anode/cathode electrode materials 13 .…”

Data-Driven Predictive Electrochemical Behavior of Lignin-Based SupercapacitorsviaMachine Learning

“…To meet the demands in energy storage, advanced electrode materials need to be developed . Many researchers have focused on better understanding electric double-layer capacitors, or supercapacitors, for renewable energy sources. − These supercapacitors demonstrate clear potential for use in industrial and consumer electronics due to their notable characteristics such as high power density, exceptional retention, fast charge rate, and adaptability to strain . In our recent study, an alkaline lignin-based supercapacitor decorated with nickel tungstate (NiWO 4 ) nanoparticles was synthesized and characterized by cyclic charge–discharge tests.…”