High‐Performance Sodium‐Ion Battery Anode via Rapid Microwave Carbonization of Natural Cellulose Nanofibers with Graphene Initiator

Abstract

Cellulose is a promising natural bio‐macromolecule due to its abundance, renewability and low cost. Here, a new method is developed to prepare pre‐sodiated carbonaceous anodes for sodium‐ion batteries (SIBs) from cellulose nanofibers (CNFs) under microwave irradiation for potential ultrafast and large‐scale manufacturing. While direct carbonization of CNFs through microwave treatment is usually impossible due to the weak microwave absorption of CNFs, it is found that a small amount of reduced graphene oxide (rGO) can act as an effective initiator. Microwaving rGO releases extremely high energy, giving rise to local ultrahigh temperature as well as ultrahigh heating rate, which then induces the fast carbonization of CNFs and the production of pre‐sodiated carbonaceous materials within seconds. The sodium in the carbonaceous materials, introduced from the carbonization of CNFs containing sodium‐ion carboxyl, offer favorable spaces for sodiation/desodiation, which improves the electrochemical performance of the sodium‐inserted carbonaceous anode. When the microwaved rGO‐CNF (MrGO‐CNF) is used as an anode for SIBs, a high initial capacity of 558 mAh g−1 is delivered and the capacity of 340 mAh g−1 remains after 200 cycles. The excellent reversible capacity and cycling stability indicate MrGO‐CNF a promising anode for sodium‐ion batteries.

High Capacity Adsorption—Dominated Potassium and Sodium Ion Storage in Activated Crumpled Graphene

“…The Na/Na + cycled A-CG electrode also well maintained its morphology and showed a similar integrated I G /I D ratio (0.66) to pristine A-CG, indicating the good structural stability for Na storage. As shown in Table S2, Supporting Information, [25,26,33,46,61,[84][85][86][87][88][89][90][91][92][93] the cyclability of the A-CG electrode versus Na/Na + is also highly favorable as compared to state-of-the-art sodium carbons.…”

On the underestimated influence of synthetic conditions in solid ionic conductors

“…In the case of battery materials, numerous electrode materials, e.g. intercalation-type cathodes [144][145][146] and carbon-based anodes, 147,148 have been synthesized via microwave methods. 149 Despite the emerging use of the microwave synthesis in various elds, there are only a few reports on the successful synthesis of solid electrolytes.…”

Applications of Nanocellulose/Nanocarbon Composites: Focus on Biotechnology and Medicine

“…Carbon nanofibers can be created by carbonization of cellulose nanofibers originating from bacterial nanocellulose [21,23,161], urea [161], filter paper [162] or plant-derived cellulose [22,24]. Another method of preparing carbon nanofibers is chemical vapor deposition (CVD; [25]).…”

“…In another study, highly conductive freestanding cross-linked carbon nanofibers, derived from bacterial cellulose in a rapid plasma pyrolysis process, were used as substrates for the growth of vertically-oriented graphene sheets for constructing alternating current filtering supercapacitors [23]. A small amount of rGO can also act as an effective initiator of carbonization of cellulose nanofibers through microwave treatment [24]. Carbonization of aerogels, prepared from a mixture of PVA, cellulose nanofibers and GO by freeze-drying, enhanced the hydrophobic properties, the specific surface area and the adsorption capacity of these aerogels.…”