Biomass-Derived Nitrogen-Doped Carbon Nanofiber Network: A Facile Template for Decoration of Ultrathin Nickel-Cobalt Layered Double Hydroxide Nanosheets as High-Performance Asymmetric Supercapacitor Electrode

Abstract

The development of biomass-based energy storage devices is an emerging trend to reduce the ever-increasing consumption of non-renewable resources. Here, nitrogen-doped carbonized bacterial cellulose (CBC-N) nanofibers are obtained by one-step carbonization of polyaniline coated bacterial cellulose (BC) nanofibers, which not only display excellent capacitive performance as the supercapacitor electrode, but also act as 3D bio-template for further deposition of ultrathin nickel-cobalt layered double hydroxide (Ni-Co LDH) nanosheets. The as-obtained CBC-N@LDH composite electrodes exhibit significantly enhanced specific capacitance (1949.5 F g(-1) at a discharge current density of 1 A g(-1) , based on active materials), high capacitance retention of 54.7% even at a high discharge current density of 10 A g(-1) and excellent cycling stability of 74.4% retention after 5000 cycles. Furthermore, asymmetric supercapacitors (ASCs) are constructed using CBC-N@LDH composites as positive electrode materials and CBC-N nanofibers as negative electrode materials. By virtue of the intrinsic pseudocapacitive characteristics of CBC-N@LDH composites and 3D nitrogen-doped carbon nanofiber networks, the developed ASC exhibits high energy density of 36.3 Wh kg(-1) at the power density of 800.2 W kg(-1) . Therefore, this work presents a novel protocol for the large-scale production of biomass-derived high-performance electrode materials in practical supercapacitor applications.

Macroscopic‐Scale Three‐Dimensional Carbon Nanofiber Architectures for Electrochemical Energy Storage Devices

“…Furthermore, one compelling advantage of this material is the green synthesis without adding any poisonous agents. Later, some researchers started to prepare many CNF nanocomposites derived from BC, including CNF@Co aerogels, [102] CNF/SnO 2 aerogels, [103] MoS 2 nanoparticles/CNF foam, [104] MoS 2 nanoleaves/CNFs, [105] porous CNFs, [106] CNFs/Pt nanoparticles, [107] nickel-cobalt layered double hydroxide (Ni-Co LDH) nanosheets/nitrogen-doped CNFs, [108] and CNFs/amorphous Fe 2 O 3 . [109] Raw cotton, a typical natural resource, is also used as raw material for fabricating CNF aerogels.…”

“…3D nitrogen-doped porous CNFs can be prepared using our CNF gel without adding any activation as the electrodes of supercapacitors, which exhibit hierarchical structure with reasonable distribution of mesopores and micropores. Compared to the carbon materials with single-sized pores, the [57][58][59][60][61][62][63][64]72] High surface areas; low volume density Thermal transformation approach CNF gels derived from thermal transformations of BC [16,70,85,86,[102][103][104][105][106][107][108][109][110][111][112][113] CVD technique 3D CNF/graphene networks [116] 3D CNF films Template-assisted approach Carbon cloth, carbon papers and carbon fiber felt-based 3D CNF films [128][129][130][131][132][133][134][135][136][137][139][140][141][142][143][144][145][146][147]…”

“…Later, Miao and Liu et al obtained nitrogen-doped CNF gels by one-step carbonization of polyaniline coated BC nanofibers and CNF gels deposited with ultrathin Ni-Co LDH nanosheets. [108] The asymmetric supercapacitors constructed with these two materials as electrodes exhibit a high energy density of 36.3 W h kg -1 at the power www.advancedsciencenews.com density of 800.2 W kg -1 . Chen and Shen et al used acicular Co 9 S 8 nanorod arrays as positive materials and Co 3 O 4 @RuO 2 nanosheet arrays as negative materials on woven carbon fabrics for flexible asymmetric supercapacitors.…”

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

“…Moreover, in nature, the biomass material with fibrous structure can be found everywhere, such as flax [55], ramie [56,57], stem bark [58], lotus seedpods [59], bacterial cellulose [24,[60][61][62][63][64], because they usually contain lignin and cellulose. It is wellknown that electrospinning is a powerful and simple technique for fiber production [65].…”

“…Importantly, the nature usually gives biomass a variety of microstructures, which could be used as precursors for preparing carbon materials with specific structures. Miraculously, biomassderived carbon materials can also inherit or evolve special microstructures including 0D spherical structure [21,22], 1D fibrous structure [23,24], 2D lamellar structure [25,26] and 3D skeleton structure [27][28][29], as shown in Fig. 1.…”