An enhanced three-stage model for sodium storage in hard carbons

Abstract

A comprehensive understanding of the sodium storage mechanism in hard carbons is essential for developing more efficient anode materials and improving the electrochemical performance of sodium-ion batteries. The mechanism has been the subject of ongoing debate, particularly regarding the role of intercalation, which we found to be insignificant in our study. By combining electrochemical analyses with operando characterization techniques, we propose a refined model of sodium storage in hard carbons. Our findings reveal a three-stage process: first, a fast-capacitive mechanism dominates in the slope region; second, a transition phase occurs at the early plateau, where faradaic processes become significant at the carbon micropore inner surface; and finally, micro- and slit-pore filling becomes dominant at the late plateau, driven by a multilayer-like deposition of quasimetallic sodium in the micropores. We believe this refined mechanism promotes a better understanding of the sodium storage mechanism in hard carbons and provides the basis for the rational design of carbon anode materials with superior performance for sodium-ion batteries.

Graphical abstract: An enhanced three-stage model for sodium storage in hard carbons

Supplementary files

Article information

Article type
Communication
Submitted
18 Dec 2024
Accepted
21 May 2025
First published
05 Jun 2025
This article is Open Access
Creative Commons BY license

Energy Environ. Sci., 2025, Advance Article

An enhanced three-stage model for sodium storage in hard carbons

E. O. Eren, E. Senokos, E. Scoppola, Z. Song, M. Antonietti and P. Giusto, Energy Environ. Sci., 2025, Advance Article , DOI: 10.1039/D4EE06029F

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements