Biomass-derived Carbon Electrode Research Articles

Algae Derived Carbon from Hydrothermal Liquefaction as Sustainable Carbon Electrode Material for Supercapacitor

With the worldwide awareness of sustainability, biomass-derived carbon electrode materials for supercapacitors have attracted growing attention. In this research, for the first time, we explored the feasibility of making use of the carbon byproduct from hydrothermal liquefaction (HTL) of microalgae, termed herein as algae-derived carbon (ADC), to prepare sustainable carbon electrode materials for high-performance supercapacitor development. Specifically, we investigated carbon activation with a variety of activating reagents as well as N- and Fe-doping of the obtained ADC with the intention to enhance its electrochemical performance. We characterized the structure of the activated and doped ADCs using scanning electron microscope (SEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and BET surface area and pore analysis, and correlated the ADCs’ structure with their electrochemical performance as evaluated using cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), impedance, and cycle stability through an assembled symmetric two-electrode cell with 1 M H2SO4 as electrolyte. It was found that the ADC that is activated using KOH (KOH-ADC) showed the best electrochemical performance, and its specific capacitance was 14.1-fold larger with respect to that of the raw ADC and reached 234.5 F/g in the GCD test at a current density of 0.5 A/g. The KOH-ADC also demonstrated excellent capacitance retention (97% after 10,000 cycles at a high current density of 10 A/g) for stable long-term operations. This research pointed out a promising direction to develop sustainable electrode materials for supercapacitors from the carbon byproduct produced after HTL processing of algae.

Impact of electrolyte concentration on electrochemical performance of Cocos nucifera Waste-Derived High-Surface carbon for green energy storage

The increasing popularity of utilizing biomass's natural structure represents a promising avenue for sustainable innovation, as it taps into the inherent characteristics of organic materials to address various environmental and industrial challenges. Researchers and industries continue to explore the full potential of biomass in creating more sustainable and efficient solutions. The transformation of biomass into carbon materials is an indirect means of utilizing CO2 as a carbon source, thus contributing to the sustainable development of energy storage technologies and also in pollution reduction. In the quest for sustainable energy solutions, this research unveils a cost-effective approach to supercapacitor development by harnessing the untapped potential of Cocos nucifera trunk sawdust-derived high-surface carbon (CHSC). Through a meticulous process involving ZnCl2 treatment and KOH activation at varying temperatures, CHSC-700 emerges as a standout electrode material with exceptional structural characteristics, boasting enhanced graphitization and a specific surface area of 1153.72 m2/g. Further, the study delved into the nuanced relationship between electrolyte concentration and supercapacitor performance, pinpointing 6 M KOH as the optimal condition. In 6 M KOH, the electrode exhibits a maximum specific capacitance of 559.27F/g at the current density of 0.5 A/g with outstanding cyclic stability, retaining 80.37 % capacitance after 20,000 cycles and an impressive energy density of 18.92 Wh/kg and power density of 246.75 W/kg. This systematic exploration provides valuable data for understanding the biomass-derived carbon electrode's behaviour under various electrolyte concentrations, offering crucial information for optimizing its performance in practical applications, such as energy storage devices.

Electroadsorption desalination performance of carbon materials derived from coconut shell without membrane separation

This study investigated coconut shells, an abundant and low-cost raw material, as the precursor for activated carbon preparation, and applied a carbonization activation method to prepare carbon materials under different activation conditions. The differences in the performance of biomass derived carbon materials as capacitive deionization (CDI) electrodes were studied under conditions of different activators, activator doses, and activation temperatures. Compared with commercial coconut shell activated carbon, studies have shown that biomass derived carbon electrodes obtained under the optimal preparation conditions of NaOH as the activator, a carbonizer to activator ratio of 1:3, and an activation temperature of 800 ℃ have an excellent electro adsorption performance and the potential to be used as a CDI electrode material. The salt adsorption capacity (SAC) of activated carbon made with coconut shell derived carbon materials after 20 min of electro adsorption reached a maximum of 11.47 mg/g. After 10 repeated uses, its SAC remained at the original 90.58%, demonstrating an excellent cycling stability.

Pine-derived porous carbon for efficient capacitive deionization and the role of its hierarchical pore structure

Capacitive deionization (CDI) is a low-energy, eco-friendly, and economically viable technology for seawater desalination. In the desalination process of CDI, the pore structure characteristics of electrode materials play a crucial role. In this study, the carbon materials with a hierarchical pore structure were prepared through high-temperature carbonization and KOH activation using pine powder as raw material. When the pine-derived porous carbon (PPC) was used as an electrode material, it was found that its specific capacitance is remarkably consistent with the specific surface area of the mesopores. This discovery provides guidance for further optimization and regulation of biomass-derived carbon electrode materials. The desalination performance of the PPC electrode was studied in detail by CDI and flow-electrode capacitive deionization (FCDI) devices. In NaCl solution with an initial concentration of 700 ppm, the equilibrium adsorption capacities in CDI and FCDI systems are 24.96 mg g−1 and 23.12 mg g−1, respectively. Particularly in FCDI tests, the average adsorption rate reaches 23.3 μg cm−2 min−1, and the desalination rate reaches 98.96 %. The PPC shows an excellent desalination performance, making it a promising efficient electrode material for electrochemical desalination.

Effective chromium mitigation using phosphorous doped bio carbon electrode via capacitive deionisation

ABSTRACT Capacitive deionisation (CDI) is an emerging eco-economic water reclamation technology that can remove inorganic salts and heavy metals. Biomass-derived carbon electrodes have attracted the scientific communities in recent years due to their economic feasibility and sustainability. However, electrochemical performance needs to be improved to achieve durability and reusability. Hence, the present study develops rice straw-derived phosphorous-doped (P-doped) carbon as an electrode for mitigating Cr(VI) ions. Phosphorus doping of biocarbon electrodes enhances their electrochemical properties, including increased electrical conductivity, improved charge storage capacity, and enhanced ion adsorption capabilities. Here, Phosphoric acid plays a dual role of activation and doping that enhances the physico-electrochemical properties. The synthesised material was found to be P-doped carbon with better pore distribution, which was confirmed through FESEM-EDX analysis. Further, the physicochemical properties of the electrode material are enriched with carbon and possess an enhanced surface area of 753 m2/g. The cyclic voltammetry shows the specific capacitance of 67 F/g for the Cr(VI) ions, which was found to be 15 times more than the non-doped carbon. CDI studies were performed with optimisation of operational parameters and found that mitigation of Cr(VI) ions was efficient at pH 2 for the applied voltage of 2V. The electrode’s performance with real-time chrome wash effluent confirms its potentiality and has better scope upon optimisation. The experimental data fits well with pseudo first-order kinetics, which ensures the nature of electrosorption is physisorption.

Solar irradiated construction of coordinatively unsaturated Znx+ (0

Biomass-derived carbon is regarded as a potential replacement for commercial graphite carbon for the anode of powerful lithium-ion batteries (LIBs), because of its abundance and ecological advantage. In this research, biomass-derived carbon is prepared from natural Carex meyeriana Kunth, and the biomass-derived carbon electrode with coordinatively unsaturated Znx+(0 < x < 2) sites is synthesized by solar irradiation. The Znx+(0 < x < 2) electrode is used as the LIBs anode. It provides a highly specific capacity of 638.6 mAh g−1 at 200 mA g−1 after 900 cycles and an outstanding cycling capacity of 614.9 mAh g−1 at 1000 mA g−1 after 1000 cycles. The capacity of the electrode exceeds the majority of reported carbonaceous anodes. This study presents a practical strategy to prepare novel and low-cost carbonaceous anode. The resulting anode has promising potential for use in advanced LIBs and other energy storage devices due to its excellent Li+ storage capability.

Soft-template hydrothermal synthesis of N and B co-doped walnut-shaped porous carbon spheres with hydrophilic surfaces for supercapacitors

Biomass-derived carbon electrodes have attracted attention for alternative energy storage devices. However, it remains a challenge to obtain a hydrophilic surface while preserving the structure, stability, and reactivity. N and B co-doped walnut-shaped porous carbon spheres with hydrophilic surfaces were prepared by hydrothermal carbonization of glucosamine, boric acid, and triblock copolymers, followed by chemical vapor phase oxidation. Walnut-shaped structure can shorten the electron and ion transport pathways and improve diffusion efficiency. N and B atoms doped in the forms of pyridine N (N-6), pyrrole N (N-5), graphite N (N-Q), N oxide (N-Ox), or N-B, as well as CB3, CB2O, CBO2, or B-N can improve the stability, conductivity, and reactivity. Hydrophilic surface can promote the wetting of the electrolyte on carbon electrodes. Therefore, N and B co-doped walnut-shaped porous carbon spheres exhibit useful electrochemical performance. The specific capacitance reaches 281F·g−1 at a current density of 0.2 A·g−1, and the rate performance reaches 75% at 5 A·g−1. The assembled symmetrical supercapacitor shows a high specific capacitance of 189 F·g−1 at 0.1 A·g−1 and an energy density of 6.56 W·h·kg−1. Furthermore, it exhibits a high cycle stability after 5000 cycles at 2 A·g−1, maintaining 95% of initial specific capacitance.

Biomass-Derived Carbon Electrodes for High-Performance Supercapacitors.

Supercapacitors with the performance advantages of high-power density are emerging materials for energy storage/conversion systems that can combat climate change caused by CO2 emissions and are of importance with the development of electronic products and artificial intelligence. But rationally preparing high-performance electrode with high mass-loading quantity remains challenge. Herein, we have opted for chitosan as well-structured binding agent to combine with active carbon (SSP-900), a 3D hierarchical micro-meso-macro porous biochar previously obtained, to synthesize high mass-loading freestanding electrode. Especially, the freestanding material (C1000 G0.2 ), owning 0.2 g SSP-900 and suffering carbonization at 1000 °C exhibits high specific surface area of 389.3 cm2 g-1 , and self-doped N, O (2.75 %, 5.64 %). That awards C1000 G0.2 outstanding electrochemical properties, including high specific mass capacitance of 199.2 F g-1 , splendid specific area capacitance of 4.37 F cm-2 in 21.93 g cm-2 , which is more competitive than conventional freestanding materials. Symmetrical supercapacitor with mass loading of 12 mg is assembled and exhibits large specific capacitance of 65 F g-1 , high energy density of 32.5 Wh kg-1 under the power density of 90.4 W kg-1 , and capacitance stability of 98 % after 10,000 cycles. The distinguished electrochemical performance of freestanding electrodes supplies prospective application for storing/converting electrical energy from intermittent solar and wind.

Sustainable Biomass-Derived Carbon Electrodes for Potassium and Aluminum Batteries: Conceptualizing the Key Parameters for Improved Performance.

The development of sustainable, safe, low-cost, high energy and density power-density energy storage devices is most needed to electrify our modern needs to reach a carbon-neutral society by ~2050. Batteries are the backbones of future sustainable energy sources for both stationary off-grid and mobile plug-in electric vehicle applications. Biomass-derived carbon materials are extensively researched as efficient and sustainable electrode/anode candidates for lithium/sodium-ion chemistries due to their well-developed tailored textures (closed pores and defects) and large microcrystalline interlayer spacing and therefore opens-up their potential applications in sustainable potassium and aluminum batteries. The main purpose of this perspective is to brief the use of biomass residues for the preparation of carbon electrodes for potassium and aluminum batteries annexed to the biomass-derived carbon physicochemical structures and their aligned electrochemical properties. In addition, we presented an outlook as well as some challenges faced in this promising area of research. We believe that this review enlightens the readers with useful insights and a reasonable understanding of issues and challenges faced in the preparation, physicochemical properties and application of biomass-derived carbon materials as anodes and cathode candidates for potassium and aluminum batteries, respectively. In addition, this review can further help material scientists to seek out novel electrode materials from different types of biomasses, which opens up new avenues in the fabrication/development of next-generation sustainable and high-energy density batteries.

Ultrahigh coulombic efficiency in alkali metal incorporated biomass derived carbon electrode

In order to facilitate higher stability and fast charging of the energy storage devices, it is also essential to increase their coulombic efficiency. The most common approaches to increase the coulombic efficiency are either by (i) introducing capacitive behaviour or (ii) tuning parasitic electrochemical reactions in batteries. Here we demonstrate a novel approach to facilitate ultra high coulombic efficiency in supercapacitors by introducing parasitic electrochemical processes in biomass derived carbon (BDC) based electrodes. Three different BDCs were synthesized by varying activating agents (KOH and NaOH) and carbonization temperatures (600 and 800 ℃). These carbon samples captured some portion of alkali metals from their respective activating agents. The trapped alkali metals in the carbon matrix eventually participate in parasitic electrochemical processes to provide ultrahigh coulombic efficiency (>115 %) for the first few thousand charge discharge cycles. Finally, an asymmetric supercapacitor (ASC) was fabricated using the prepared BDC as the negative electrode and a comparatively slow V2O5 electrode as a positive. The ASC can retain about 98 % of its initial capacitance even after 10,000 cycles and exhibits high coulombic efficiency. It provides an energy density of 0.196 mWhcm−3 while maintaining a high power density of 190.41 mWcm−3.

Upcycling of cattle manure for simultaneous energy recovery and supercapacitor electrode production

Organic waste, such as cattle manure, is a serious matter of concern because of its disruptive impact on the environment. Even though disposal and reclaim of cattle manure represent the first lines of intervention to solve this problem, upcycling strategies should eventually be essential to reconvert huge amounts of the waste. In the present study, a pyrolysis process was used to reclaim value from cattle manure. Through the process, cattle manure was transformed into pyrolytic gas, pyrolytic liquid, and porous carbon material. The porous carbon material was further carbonized followed by an activation step to make a supercapacitor electrode. The electrode of a hierarchical porous carbon (termed as CMPC) is formed via carbonization and activation processes of solid residue derived from the pyrolysis of cattle manure. The bicontinuous structure of CMPC provide good ion and electron transport pathways, enabling fast charge-discharge. Specifically, in a basic solution electrolyte, CMPC electrode exhibits significant specific capacitance of 161 F g−1 at 0.4 A g−1, comparable to or even larger than other biomass-derived carbon electrodes, and high rate-performance (62% of low-capacitance). It also shows long cycle lives for at least 10,000 charge-discharge cycles at a constant current of 2.7 A g−1. As the pyrolytic gas and pyrolytic liquid had higher heating values of 7.6 MJ kg−1 and 8 MJ kg−1, respectively, they can potentially be used as fuels to supply heat and energy to the pyrolysis process. The cattle manure upcycling process could greatly contribute to the reduction in greenhouse gas emissions.

Construction of nickel ferrite nanoparticle-loaded on carboxymethyl cellulose-derived porous carbon for efficient pseudocapacitive energy storage

The preparation of biomass-derived carbon electrode materials with abundant active sites is suitable for development of energy-storage systems with high energy and power densities. Herein, a hybrid material consisting of highly-dispersed nickel ferrite nanoparticle on 3D hierarchical carboxymethyl cellulose-derived porous carbon (NiFe2O4/CPC) was prepared by simple annealing treatment. The synergistic effects of NiFe2O4 species with multiple oxidation states and 3D porous carbon with a large specific surface area offered abundant active centers, fast electron/ion transport, and robust structural stability, thereby showing the excellent performance of the electrochemical capacitor. The best performing sample (NiFe2O4/CPC-800) exhibited a superior capacitance of 2894F g−1 at a current density of 0.5 A g−1. Encouragingly, an asymmetric supercapacitor with NiFe2O4/CPC-800 as a positive electrode and activated carbon as a negative electrode delivered a high energy density of 135.2 W h kg−1 along with an improved power density of 10.04 kW kg−1. Meanwhile, the superior cycling stability of 90.2% over 10,000 cycles at 5 A g−1 was achieved. Overall, the presented work offers a guideline for the design and preparation of advanced electrode materials for energy-storage systems.

Effect of pH and activation on macroporous carbon derived from cocoa-pods for high performance aqueous supercapacitor application

Activated carbon (AC) electrodes for supercapacitors (SCs) are typically prepared by high-temperature carbonization processes and involves multiple stages of activation. Herein, we report a facile, hydrothermal carbonization of biomass cocoa-pods via ZnCl2 activation during pyrolysis that results in macro-porous carbon (AC1). ZnCl2 serves as a template and interacts with the cocoa-pods promoting efficient carbonization reaction resulting in large specific surface area (SSA = 1061.6 m2g-1) macro-pores, while the AC2 (KOH activation) results in SSA of 819.79 m2g-1. FESEM micrographs reveal well-defined large-size pores of ∼3.2 μm diameter that facilitate easy access of the electrolyte ions into the pores thereby contributing to the efficient charge-storing ability suitable for SCs performance. The porous AC1 exhibits high specific capacitance and excellent rate capability over a wide pH range from 2.5 to 13.5. The highest specific capacitance (320 Fg-1) was obtained in 6 M KOH (pH = 13.5) at 1 Ag-1 due to the high ionic conductivity and high mobility of OH− anions in KOH electrolyte. The symmetrical SC with AC1 as the electrode delivers a high energy density of 126 Whkg−1 at a power density of 11,520 Wkg-1 with a wide operating voltage of 1.7 V in 1 M Li2SO4 (pH = 5.6) electrolyte. AC1 delivered higher power density than AC2 (KOH-activation) and 100% capacitance retention over 24,000 cycles. The work demonstrated here outlines a new strategy for optimizing the efficient performance of biomass derived carbon electrodes in aqueous electrolytes of varying pH.

Lignocellulosic Biomass-Derived Carbon Electrodes for Flexible Supercapacitors: An Overview.

With the increasing demand for high-performance electronic devices in smart textiles, various types of flexible/wearable electronic device (i.e., supercapacitors, batteries, fuel cells, etc.) have emerged regularly. As one of the most promising wearable devices, flexible supercapacitors from a variety of electrode materials have been developed. In particular, carbon materials from lignocellulosic biomass precursor have the characteristics of low cost, natural abundance, high specific surface area, excellent electrochemical stability, etc. Moreover, their chemical structures usually contain a large number of heteroatomic groups, which greatly contribute to the capacitive performance of the corresponding flexible supercapacitors. This review summarizes the working mechanism, configuration of flexible electrodes, conversion of lignocellulosic biomass-derived carbon electrodes, and their corresponding electrochemical properties in flexible/wearable supercapacitors. Technology challenges and future research trends will also be provided.

Osmanthus fragrans-derived N-doped porous carbon for supercapacitor applications

Biomass-derived carbon electrodes with precise and controllable biological structure have attracted more and more attention in recent years owing to their wide availability, renewability, and low cost. In this study, we used Osmanthus as a raw material in the preparation of nitrogen-doped porous carbon by using a simple carbonization/activation method. It was observed that the prepared biomass carbon had a three-dimensional hierarchical porous, including micropores and mesopores, and the highest specific surface area was 2078.3 m2 g−1. The electrochemical performance of Osmanthus fragrans mainly depends on its microporous/mesoporous performance. The specific capacitance of sample OC1-2 in a 3-M KOH electrolyte reached 351 F g−1 at a current density of 0.5 A g−1; after 10000 cycles, the capacitance retention rate reached 93.51%. At a specific density of 700 W kg−1, the specific density reached 13.86 Wh kg−1. This study shows that Osmanthus fragrans-derived biomass porous carbon electrode material has great potential for energy storage.

Tuning of Reciprocal Carbon-Electrode Properties for an Optimized Hydrogen Evolution.

Closing the material cycle for harmful and rare resources is a key criterion for sustainable and green energy systems. The concept of using scalable biomass‐derived carbon electrodes to produce hydrogen from water was proposed here, satisfying the need for sustainability in the field of chemical energy conversion. The carbon electrodes exhibited not only water oxidation activity but also a strong self‐oxidation when being used as anode for water splitting. The carbon oxidation, which is more energy‐favorable, was intentionally allowed to occur for an improvement of the total current, thus enhancing the hydrogen production on the cathode side. By introducing different earth‐abundant metals, the electrode could be well adjusted to achieve an optimized water/carbon oxidation ratio and an appreciable reactivity for practical applications. This promising methodology may become a very large driver for carbon chemistry when waste organic materials or biomass can be converted using its intrinsic energy content of carbon. Such a process could open a safe path for sub‐zero CO2 emission control. The concept of how and which parameter of a carbon‐based electrode can be optimized was presented and discussed in this paper.

Hierarchical porous carbon composite constructed with 1-D CNT and 2-D GNS anchored on 3-D carbon skeleton from spent coffee grounds for supercapacitor

In recent years, biomass-derived carbon electrode materials for energy storage have attracted intensive attention in terms of their natural unique structure, widespread availability and low cost. Herein, a unique hierarchical porous carbon composite material (CGCM@GNS&CNT) was facilely constructed on 3-D carbon skeleton by anchoring 2-D graphene nanosheet (GNS) and 1-D carbon nanotube (CNT) through self-assembling method. The CGs with abundant macroscopic pores were utilized as 3D carbon skeleton, CNT and GNS anchored on them were applied to enhance the specific surface area (SSA) and electrical conductivity. The composite material exhibits large SSA of 460 m2 g−1, interconnected conductive network and inherent N, O doping. The CGCM@GNS&CNT electrode achieves a high areal capacitance of 441 mF cm−2 and volumetric capacitance of 90 F cm−3 at 1 mA cm−2 in 1.5 M Na2SO4 electrolyte. More importantly, the CGCM@GNS&CNT-based symmetric supercapacitor affords a remarkable energy density of 31 μWh cm−2 at a power density of 800 μW cm−2 in 1.5 M Na2SO4. The capacitance retention and coulombic efficiency can retain 102.5% and 100.5% over 2000 cycles, respectively, confirming its superb charge/discharge stability and long-term reversibility. These signify that CGCM@GNS&CNT material holds a considerable promise for electrode application in high-performance supercapacitor.

Nitrogen, sulfur co-doped hierarchical carbon encapsulated in graphene with “sphere-in-layer” interconnection for high-performance supercapacitor

Rational design of electrode with hierarchical charge-transfer structure and good electronic conductivity is important to achieve high specific capacitance and energy density for supercapacitor, but it still remains a challenge. Herein, a nitrogen, sulfur co-doped pollen-derived carbon/graphene (PCG) composite with interconnected “sphere-in-layer” structure was fabricated, in which hierarchically pollen-derived carbon microspheres can serve as “porous spacers” to prevent the agglomeration of graphene nanosheets. The optimized PCG composite prepared with 0.5 wt% of graphene oxide (PCG-0.5) exhibited high specific capacitance (420Fg−1 at 1Ag−1), rate performance (280Fg−1 at 20Ag−1), and excellent cycling stability with 94% of capacitance retention after 10,000 cycles. The symmetrical device delivered a remarkable energy density of 31.3Whkg−1 in neutral medium. Moreover, density functional theory calculation revealed that PCG electrode possessed the accelerated charge transfer and enhanced electronic conductivity, thus ensuring a remarkable electrochemical performance. This work may afford an effective strategy for the development of biomass-derived carbon electrodes with novel charge-transfer structure toward supercapacitor applications.

Enhanced performance study of microbial fuel cell using waste biomass-derived carbon electrode

The microbial fuel cell (MFC) efficiency was assessed by using biochar electrode. Electrodes were made of silicon (Si0.4), zinc (Zn0.4), and copper (Cu0.4) in 40% proportions mixed with derived waste coconut shell (CS) biochar materials after the carbonization process. The specific surface area of CS-Si0.4 (0.1920 m2 g−1), CS-Zn0.4 (0.2025 m2 g−1), and CS-Cu0.4 (0.2532 m2 g−1) is higher when compared to Graphite Particle (GP) (0.2165 m2 g−1). Electrodes’ power production outputs were CS-Si0.4 ((19.22 ± 0.5) mW m−2), CS-Zn0.4 ((26.40 ± 0.6) mW m−2), and CS-Cu0.4 ((47.04 ± 0.5) mW m−2) similar to GP ((32 ± 0.5) mW m−2). Experimental results show that the CS-Cu0.4 electrode provides maximum power output and efficiency. The inclusion of metals will increase surface area of biochar electrodes, and it increases the microbial fuel cell efficiency. The CS-Cu0.4 electrodes are therefore feasible, biocompatible, and cost-effective for environmentally sustainable systems.

“Plains–Hills”: A New Model to Design Biomass-Derived Carbon Electrode Materials for High-Performance Potassium Ion Hybrid Supercapacitors

Enhancing the pseudocapacitance of carbon electrodes by doping them with heteroatoms becomes one promising way for fabricating high energy density supercapacitors. Nevertheless, rich doping with he...