Interfacial-bulk electrochemistry of sodium-ion storage in multiwalled carbon nanofiber anode with incorporated Mn−N4 single-atoms
Journal
Chemical Engineering Journal
Journal Volume
525
Start Page
169716
ISSN
1385-8947
Date Issued
2025-12-01
Author(s)
Yadav, Anubha
Pathak, Prakash Kumar
Matsagar, Babasaheb M.
Patil, Rahul
Chen, Norman C.-R.
Urkude, Rajashri R.
Ujihara, Masaki
Salunkhe, Rahul R.
Dutta, Saikat
Abstract
Atomic interface engineering using Mn-Nx-Cx structural unit with Mn-Nx moiety on carbonaceous materials can be a major strategy to regulate interfacial/bulk electrochemistry by inducing a local electric field. In this study, we aim to incorporate Mn-rich layers that enhance structural integrity while maintaining a low redox voltage, which facilitates the incorporation of Mn-Nx atomic dispersion in multiwalled N-doped carbon nanofiber (N-CNF). Our X-ray absorption spectroscopy (XAS) analysis and aberration-corrected angle annular dark-field scanning transmission electron microscopy (AC-HAADF-STEM) analysis support two types of Mn-Nx regions with higher and lower atomic density on N-CNF. Incorporating Mn-N4 single atom modulates the local electrical field for fast bulk Na+ transportation to enhance intrinsic electrical conductivity with numerous additional reaction sites. Notably, the Mn-N4-N-CNF anode in the coin cell demonstrates an outstanding rate capability of 417 mAh g−1 at 20 mA g−1 and stable charge-discharge performance for current rates 20–2000 mA g-1 along with a long cycling stability test at 1000 mA g−1. Mn-N4-N-CNF cell retained 95 % of the highest capacity, nearly 100 % Columbic efficiency, and a 500-cycle life. This work provides an understanding of a multiwalled N-CNF multilayer with incorporated Mn-N4 single atom, achieving a controllable defect and morphology engineering to offer an advanced anode material with faster Na+ charge transfer for SIBs. The GITT profile and the calculated diffusion coefficient suggest an improved diffusion of Na+ enabled by an effect of Mn-SA and N-CNF-multi-walled structure.
Subjects
Atomic interface
Charge-discharge
Electric field
Mn-N4-single-atom
n-doped nanofiber
Sodium-ion diffusion
Publisher
Elsevier BV
Type
journal article