Three‐Dimensional Graphene‐based N‐doped Carbon Composites as High‐Performance Anode Materials for Sodium‐ion Batteries

Abstract

An itrogen-doped carbon layer coating on a3 D graphene framework (NCL@GF) was produced by the in-situ polymerizationo fau niform polyimide layer on the graphene framework surface and ac arbonization process. The NCL@GF exhibited a3 Dm acroporous structure with uniform N-doped porousc arbonl ayers and ah igh 5.4 at. %n itrogen content, which not only effectively enhanced the active sites but also facilitated fast ion ande lectron transporti nt he 3D pathways. Consequently,t he NCL@GF as the anode of a sodium-ion battery (SIB) exhibited ad ischarge capacity of 357 mAh g À1 at 0.1 Ag À1 after 200 cycles, ar emarkable rate capability with ac apacity of 122 mAh g À1 at 8Ag À1 ,a nd a super long cyclel ifew ithacapacity retention of 70 %c apacity after 2500 cycles at 0.5 Ag À1 .S uch performance is superiort ot hat of previously reported carbon or graphenebased composites.Supporting information and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

Multi-scale structure optimization of boron-doped hard carbon nanospheres boosting the plateau capacity for high performance sodium ion batteries

“…The curves show the typical characteristics of carbon-based anode materials, from which two obvious peaks at $0.3 V and $1.25 V in the initial cycle represent irreversible reduction reaction between the electrolyte and electrode material, causing the formation of solid electrolyte interface (SEI) or Na + irreversible storage in the carbon matrix. 82,83 In subsequent scans, the CV proles almost overlapped, from which highly reversible Na + insertion and extraction processes in the carbon structure can be inferred. In addition, a pair of sharp redox peaks at approximately 0.01 and 0.2 V are considered to be related to the Na + insertion/extraction mechanism.…”

From 2D Graphene Nanosheets to 3D Graphene‐based Macrostructures

“…Basically, these secondary components were chosen based on their high surface area and conductivity, low mass transport resistance and easy electrode modification with fast and tunable electrochemical synthesis . Such 3D structured graphene‐based material was designed as thin films covering the electrode surface and they were especially used for applications such as electronic, sensing, solar cells, supercapacitors, batteries, electrochemical energy storage etc. The approaches described below allow to prepare higher quantities of materials in the form of monolith of often several cm 3 useful for other application field mainly environmental.…”