Biomass-derived carbon: synthesis and applications in energy storage and conversion

Abstract

The explosive growth of energy consumption hungers for highly efficient energy conversion and storage devices, whose innovation greatly depends on the development of advanced electrode materials and catalysts. Among those advanced materials explored, carbon materials have drawn much attention due to their excellent properties, such as high specific surface area and tunable porous structures. Challenges also come from global warming and environmental pollution, which require sustainable carbon-rich precursors for carbon materials. Hence, the use of biomass for carbon materials features the concept of Green Chemistry. This review has summarized the most advanced progress in biomass-derived carbon for the use of fuel cells, eletrocatalytic water splitting devices, supercapacitors and lithium-ion battery. Several synthetic strategies for synthesizing biomass-derived carbon, including direct pyrolysis, hydrothermal carbonization, and ionothermal carbonization, have been reviewed, and the corresponding formation mechanisms and prospects are also discussed. This provides fundamental insight and offers an important guideline for future design of biomass-derived carbon on specific energy application.Please do not adjust margins Please do not adjust margins process, the activators make great effects on the properties of the final products. Among those activators, KOH is very promising due to its lower activation temperature, hence leading to high yields, and well-defined micropore size distribution with ultrahigh SSA (up to 3000 m 2 /g). Through KOH activation, micropores and small mesopores can be introduced into the framework of various structured carbons. 33 The high SSA and increased micropore and mesopore volume demonstrate excellent properties in energy storage and conversion. Although, the activation mechanism of KOH is complex and it is not understood clearly, three main activation processes for KOH activation of carbon are accepted: 13 1) Potassium compounds, including KOH and some compounds (K 2 CO 3 and K 2 O) formed during the calcination process, react with carbon, generating the pore network; 2) the intermediate products (H 2 O and CO 2 ) contribute to the further development of the porosity via the gasification of carbon; 3) the as-prepared metallic K intercalate into the carbon lattices of carbon matrix effectively, leading to the expansion of the carbon lattices. The porous structure is created, after the metallic K and other K compounds are removed. Fig. 1 (a) Schematic diagram of the formation of HPCs: mixing the biomass with the "leavening" agents followed by pyrolysis under an inert gas, 34 (b) the SEM images with different mass ratio of cellulose, hemicellulose, and lignin. 35 Reproduced with permission from ref. 34, 35. Copyright©Fig. 20 (a) schemiatic mechanism of the synthesis of nanostructured silicon/porous carbon spheres; the charge-discharge curves and schematic diagram of the lithiationdelithiation process (inset) of (a) Si NPs and (c) N-SPC, and (d) their cycling performance at constant densi...

Hydrothermal Carbonization: Modeling, Final Properties Design and Applications: A Review

“…Despite its effectiveness, this chemical also leads to environmental concern due to its corrosive and harmful characteristics because of its strong alkalinity [103]. Therefore, finding effective sustainable synthesis schemes yielding highly porous materials is a challenging issue at the moment.…”

“…A review of the research in this field shows that KOH is, by far, the most used activating agent for enhancing porosity development in HCs in order to improve their supercapacitor performance [98][99][100][101][102], providing a better porosity develpment as compared to other chemical agents such as H 3 PO 4 or NaOH [103]. This compound can successfully develop the HC incipient porosity by means of the Reaction (1), followed by K 2 CO 3 decomposition into K 2 O or its reaction with carbon.…”

Porous Activated Carbons Derived from Pleurotus eryngii for Supercapacitor Applications

“…In recent years, two-dimensional (2D) nanomaterials [11] and hybrid materials [12] have attracted great interests. However, the synthesis of 2D nanosheets and hybrid materials is commonly involved with methods like arc-discharge synthesis, chemical vapor deposition, and microwave radiation, which are expensive, complicated, and sometimes harmful to the environment [13][14][15]. Now, the trend is to use biomass as a convenient and economical method for supercapacitors.…”

Biomass-derived carbon materials with structural diversities and their applications in energy storage

“…Recently, the HTC of biomass precursors, including eucalyptus sawdust [160], fungi [117,161], papyrifera bark [162], pine cones [163], tobacco rods [125], and bagasse [113], has been extensively explored for the preparation of carbon materials at 180-250°C, owing to its simplicity, cost-effective and nonpollution [164]. The chemical reaction involved in the HTC process comprises five steps: hydrolysis, dehydration, decarboxylation, polymerization, and aromatization [30]. It results in HTC carbon materials with SSA ranging from 1.3 to 250 m 2 g −1 depending on the different carbon precursors, such as peanut hull [165], palm empty fruit bunches [166], pinewood [167], sunflower stem [168], olive stone [168], walnut shell [168], hazel nutshell [169], barley straw [170], auriculariaes [117,161] and ovalbumin [171].…”

“…Moreover, the biomass-derived carbon electrodes have many advantages, such as high specific surface area (SSA), welldefined pore size distribution, excellent electric conductivity and easily modified surface chemistry [30,31]. On the one hand, numerous biomass-derived carbon materials with naturally porous or hierarchical structures of the biomass or created pores deriving from activation facilitate the electrolyte penetration and shorten the ion diffusion distance [32,33].…”