Flaky N-doped hard carbon anode material for sodium-ion batteries

Abstract

Hard carbon (HC), as a promising anode material for sodium ion batteries, its sluggish diffusion performance hinders further improvement of electrochemical performance. In the preparation process of HC materials, the screening and treatment of precursors can optimize the structure and morphology of HC products, further affecting electrochemical performance. Here, we use peptone as the precursor of HC and prepare flaky N-doped HC (PFNC) through a one-step annealing method. Benefitting from this structure, the prepared PNFC delivers a specific capacity of 315.5 mAh g-1 at a current density of 20mA g-1 with excellent rate performance and cyclic stability. This work proves that peptone is a valuable carbon precursor, opening a new avenue for further application and development of HC.

Intrinsically Nitrogen-Enriched Biomass-Derived Hard Carbon with Enhanced Performance as a Sodium-Ion Battery Anode

“…As a result, a modest but steady increase in the I D / I G value suggests that the concentration of defects increased as the carbonization temperature increased . This enhancement in the defects serve as an active sites for sodium-ion adsorption during electrochemical reactions, which is advantageous for the better storage property . The carbonization temperatures in this study represent a typical reaction temperature for the majority of HCs produced from biomass, rather than a broad range.…”

“…57 The increase in the oxygenated functional groups in HC-1200 possess better adsorption capabilities, which is beneficial for the conductivity of Na + ions for the insertion into the graphite layers. 23 The N 1s core-level spectra, on the other hand, had reduced intensity levels between the binding energies of 396 and 402 eV, as seen in Figure 5e, which primarily can be indexed into the C−N bonds in the prepared HCs. 58 In Figure 5f, it is obvious that as the carbonization temperature increases, the intensities of the functional groups, based on the O 1s and N 1s core-level spectra, gradually decrease, which reveals the removal of functional groups from the surface of the HCs.…”

“…The C 1s core-level spectra may be deconvoluted into three peaks with binding energies of 283.8, 284.5, and 286.5 eV, which are attributed to the sp 2 C carbons, sp 3 C, and C–O/C–N bonds, respectively, as shown in Figure c. , In the O 1s core-level spectra (Figure d), there are a few peaks that can be deconvoluted into binding energies of 531.6 and 533 eV, which correspond to the C–O–C and O–C–O bonds, respectively . The increase in the oxygenated functional groups in HC-1200 possess better adsorption capabilities, which is beneficial for the conductivity of Na + ions for the insertion into the graphite layers . The N 1s core-level spectra, on the other hand, had reduced intensity levels between the binding energies of 396 and 402 eV, as seen in Figure e, which primarily can be indexed into the C–N bonds in the prepared HCs .…”

“…For those diverse anodes, however, the obstacles of a high discharge potential, structural instability, low reversible specific capacity, and low initial Coulombic efficiency remain. Due to its high reversible capacity, low average potential, and outstanding cycling stability, hard carbon (HC) has the highest potential of all the carbon anode choices as a viable anode material for SIBs. , At present, this makes it appear to be among the most intriguing anode materials for SIBs …”

Hierarchically porous closed-pore hard carbon as a plateau-dominated high-performance anode for sodium-ion batteries

“…Herein, the pre-treatment of sucrose was achieved by a microwave-assisted solvothermal method to induce more defects, diverse pore-size distributions, and a high degree of compaction for spherical particles offered to prepare homogeneous electrodes for excellent sodium-ion storage. 20,21 The morphology and microstructure of the microwaved MSHCs before and after the single-step carbonization were characterized by SEM. After microwave-assisted solvothermal synthesis, the hydrochar shows a microsphere-like morphology with severe agglomeration (Fig.…”