3D Amorphous Carbon with Controlled Porous and Disordered Structures as a High‐Rate Anode Material for Sodium‐Ion Batteries

Abstract

high energy density and low self-discharge rate, lithium-ion batteries (LIBs) have been widely applied to millions of portable electronic devices and electric vehicles since 1991. [1,2] Nevertheless, driven by the rising cost of LIBs, the limited content (0.0065%) and uneven distribution of lithium resource on the earth, [3,4] post-lithium ion battery technologies have worldwidely dragged researchers' attentions. Sodium is naturally abundant and has chemical properties similar to lithium, while do not form alloys with aluminum collectors. [5][6][7] Thus, sodium-ion batteries (SIBs) have been considered as an ideal candidate for cost-effective energy storage. However, the cycling stability, rate capability, and capacity of SIBs still need to be enhanced for practical systems and further development. There still remains a challenge that high-performance and low-cost electrode materials, especially the suitable anode materials, are urgent to develop.Compared with the poor structure stability of sodium alloy, [8,9] low reversible capacity of titanium-based oxide, [10,11] and complicated strategies of composites, [12][13][14] carbon materials are regarded as the most promising anode materials of SIBs for practical applications. Various carbon materials, including graphite, [15,16] expanded graphite, [17] amorphous carbon, [18][19][20] and graphene, [21][22][23] have been investigated, which indicates favorable sodium ions de/insertion reactions in host structure due to the lattice defect and larger interlayer space. Among all the carbon anode candidates, amorphous carbon, such as hard carbon and soft carbon, has attracted much attention due to high electrochemical activity and relatively low cost. Hard carbon contains plenty of disordered structures with defects and voids, which contribute to high reversible capacities yet large initial irreversible capacity loss. [24][25][26][27] Moreover, the disordered structures in hard carbon cause low electronic conductivity and the resulting poor rate performance. [28] On the contrary, soft carbon has abundant graphitic regions yet relatively few defects, which results in high electronic conductivity and low initial Coulombic efficiency. Mesophase carbon microbead (MCMB), one of the typical soft carbon materials, has been widely used as a high-rate anode material with a reversible capacity of ≈330 mA h g −1 for LIBs. [29] However, soft carbon usually delivers a low reversible capacity Sodium-ion batteries (SIBs) have a promising application prospect for energy storage systems due to the abundant resource. Amorphous carbon with high electronic conductivity and high surface area is likely to be the most promising anode material for SIBs. However, the rate capability of amorphous carbon in SIBs is still a big challenge because of the sluggish kinetics of Na + ions. Herein, a three-dimensional amorphous carbon (3DAC) with controlled porous and disordered structures is synthesized via a facile NaCl template-assisted method. Combination of open porous structures of 3DAC, the increase...

Nickel Hollow Spheres Concatenated by Nitrogen‐Doped Carbon Fibers for Enhancing Electrochemical Kinetics of Sodium–Sulfur Batteries

“…To further investigate the carbon component, Raman characterization is carried out and presented as Figure h. The D‐band and G‐band at about 1318 and 1565 cm −1 are related to the defective and graphitic carbon, respectively, while the 2 D band at around 2780 cm −1 is associated with highly crystalline carbon material . The high I D / I G value and wide 2 D band suggest a low graphitization degree of the carbon in Ni‐NCFs composite, which is beneficial for the insertion of sodium ions during cycling.…”

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

“…Hard carbon, known as the nongraphitizable amorphous carbon comprised of randomly distributed graphitized microdomains, distorted graphene nanosheets, and voids, has been employed as a promising anode material for SIBs due to its abundant resources, low cost, and favorable space for sodium‐ion storage . Natural products, such as chitosan, cellulose, and lignin, can be converted to hard carbon materials under pyrolysis treatment due to their advantages of abundance, high accessibility and sustainability .…”

Bi2S3 Nanorods Bonding on Reduced Graphene Oxide Surface as Advanced Anode Materials for Sodium‐Ion Batteries

“…Rechargeable batteries have become one of the most important necessities in our daily life and have achieved tremendous success in both technological advances and commercial applications in recent decades . Sodium‐ion batteries (SIBs) are considered one of the most promising alternatives to the currently dominating lithium‐ion batteries (LIBs) as sodium resources are much cheaper than lithium and, in principle, unlimited on earth . The low‐cost feature of sodium could offer a high possibility for the practical applications of SIBs in large‐scale energy storage.…”