Renewable biomass‐derived carbons for electrochemical capacitor applications

Abstract

Biomass is rich, renewable, sustainable, and green resources, thereby excellent raw material for the fabrication of carbon materials. The diversity in structure and morphology of biomass are relevant in obtaining carbon materials with different structures and performances. The inherent ordered porous structure of biomass also benefits the activation process to yield porous carbons with ultrahigh specific surface area and pore volume. Besides, obtained biomass‐derived carbons (BDCs) are hard carbon with porous morphology, stable structure, superior hardness/strength, and good cycling performances when used in electrochemical capacitors (ECs). The inherent N, S, P, and O elements in biomass yield naturally self‐doped N, S, P, and O BDCs with unique intrinsic structures. In this paper, the synthesis approaches and applications of BDCs in ECs are reviewed. It shows that BDCs electrochemical performances are highly determined by their pore structures, specific surface areas, heteroatoms doping, graphitization degree, defects, and morphologies. The electrochemical performances of BDCs can further be improved by compositing with other materials, such as graphene, carbon nanofibers/nanotubes, transition metal oxides or hydroxides, and conducting polymers. The future challenges and outlooks of BDCs are also provided.

Biomass-Derived Carbons as Versatile Materials for Energy-Related Applications: Capacitive Properties vs. Oxygen Reduction Reaction Catalysis

“…The debate in the scientific community is very active and is typically directed towards one of the many possible applications. For example, in terms of capacitive applications, the most relevant factors influencing the response are: morphology, pore structure, specific surface area, heteroatom doping, degree of graphitization, and the presence of defects [21]. However, rather different, and sometimes opposing, claims can be found in the literature regarding the role of pore size and structure, the presence and the type of the heteroatoms (usually nitrogen, sulfur, phosphorus.…”

Challenges and Recent Progress on Silicon‐Based Anode Materials for Next‐Generation Lithium‐Ion Batteries

“…Otherwise, biomass materials are mentionable natural sources for commercial Si‐based anode materials, which including reed leaf, rice husk, bamboo leaf, and sugarcane bagasse. [ 101 ] The conversion of corn leaves into Si anode materials is reported via a simple aluminothermic reduction reaction without other modifications (Figure 12b). The obtained Si material inherits the structural characteristics of the natural corn leaf template delivers great rate capability of 1200 mA h g −1 at 8 A g −1 .…”

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

“…The porosity or the quality of the activated lignocellulose-derived carbon relies on different activation parameters such as temperature, time, gas flow rate, etc. [ 26 , 28 ]. Moreover, an appropriate activation agent is required for biomass to achieve high surface area or porosity due to the difference in chemical structure and composite component of precursor [ 83 ].…”

“…The possible activation mechanism of ZnCl 2 is based on the catalytic dihydroxylation and dehydration during pyrolysis process. In this process, H and O atoms are released as H 2 O, creating a micropore-rich structure in biochar [ 28 ]. Moreover, ZnCl 2 acts as a framework for carbon deposition in the activation process, and leaves voids in carbon skeleton for more pores after acid washing [ 28 ].…”

“…Several published review articles have summarized various aspects of biomass-derived porous carbon including biomass species [ 17 , 24 ], fabrication methods [ 25 , 26 ], carbon architecture [ 27 ], influencing factors of EC performance (i.e., pore characteristics, heteroatom-doping, morphology, graphitization degree, etc.) [ 28 ], and wide applications in fields such as power generation and energy storage (i.e., lithium-metal or lithium-sulfur batteries, electrolyte reservoir, separator, supercapacitors, etc.) [ 29 , 30 ].…”