Articles
  • Valorization of wastewater sludge into carbon materials for energy storage applications: feasibility and economic assessment

  • Saehee Leea, Chanwoo Kima, Uijun Leeb, Hyeonmin Joa, Hee-Dae Lima,b,* and Byoung-In Sanga,c,*

  • aDepartment of Chemical Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea
    bDepartment of Battery Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea
    cClean-Energy Research Institute, Hanyang University, 222 Wangsimni-ro, Seongdong- gu, Seoul 04763, Republic of Korea

  • This article is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The increasing accumulation of sewage sludge from wastewater treatment presents both environmental and economic concerns. This study proposes a sustainable valorization approach by converting sludge into porous carbon materials for lithium metal battery applications. Sludge underwent chemical pretreatment, pyrolysis at 800 °C, and KOH activation to yield carbon (Sludge C) with tailored structure and functionality. Physicochemical characterization confirmed a microporous structure, oxygen-rich surface groups, and partial crystallinity due to residual inorganic elements such as Si, Al, and Fe. Compared to commercial Super P, Sludge C exhibited lower lithium nucleation overpotential and improved cycling stability, attributed to its lithiophilic species and high surface area. A techno-economic analysis compared sludge carbonization with incineration, composting, and biohydrogen production. Despite higher capital costs, sludge carbonization offered promising value recovery through electrode material production. This study highlights a scalable and eco-friendly pathway for transforming sewage sludge into functional materials for energy storage, supporting waste minimization and circular bioeconomy goals.


Keywords: Sewage sludge valorization, Sludge-derived carbon, Lithiophilic interlayer, Techno-economic analysis.

This Article

  • 2025; 26(4): 606-617

    Published on Aug 31, 2025

  • 10.36410/jcpr.2025.26.4.606
  • Received on May 26, 2025
  • Revised on Jun 10, 2025
  • Accepted on Jun 11, 2025

Correspondence to

  • Hee-Dae Lim a,b and Byoung-In Sang a,c

  • aDepartment of Chemical Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea
    bDepartment of Battery Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea
    cClean-Energy Research Institute, Hanyang University, 222 Wangsimni-ro, Seongdong- gu, Seoul 04763, Republic of Korea
    Tel. +82-2-2220-0531(Hee-Dae Lim), Tel. +82-2-2220-2328(Byoung-In Sang)

  • E-mail: hdlim@hanyang.ac.kr, biosang@hanyang.ac.kr