Open AccessUltrafine TiO 2 Nanoparticle Supported Nitrogen‐Rich Graphitic Porous Carbon as an Efficient Anode Material for Potassium‐Ion Batteries
Author(s) -
Dubal Deepak P.,
Schneemann Andreas,
Ranc Václav,
Kment Štěpán,
Tomanec Ondrej,
Petr Martin,
Kmentova Hana,
Otyepka Michal,
Zbořil Radek,
Fischer Roland A.,
Jayaramulu Kolleboyina
Publication year - 2021
Publication title -
advanced energy and sustainability research
Language(s) - English
Resource type - Journals
ISSN - 2699-9412
DOI - 10.1002/aesr.202100042
Subject(s) - materials science , anode , anatase , chemical engineering , electrolyte , faraday efficiency , nanoparticle , carbon fibers , scanning electron microscope , potassium hydroxide , nanotechnology , electrode , chemistry , catalysis , composite material , photocatalysis , biochemistry , composite number , engineering
Potassium‐ion batteries (KIBs) have attracted enormous attention as a next‐generation energy storage system due to their low cost, fast ionic conductivity within electrolytes, and high operating voltage. However, developing suitable electrode materials to guarantee high‐energy output and structural stability to ensure long cycling performance remains a critical challenge. Herein, anatase TiO 2 nanoparticles are encapsulated in nitrogen‐rich graphitic carbon (TiO 2 @NGC) with hierarchical pores and high surface area (250 m 2 g −1 ) using the Ti‐based metal–organic framework NH 2 ‐MIL‐125 (Ti 8 O 8 (OH) 4 (NH 2 ‐bdc) 6 with NH 2 ‐bdc 2− = 2‐amino‐1,4‐benzenedicarboxylate) as a sacrificial template. Serving as the anode material in a K‐ion half‐cell, TiO 2 @NGC delivers a high capacity of 228 mA h g −1 with remarkable cycling performance (negligible loss over 2000 cycles with more than 98% Coulombic efficiency). The charge‐storing mechanism is underpinned using ex situ characterization techniques such as ex situ X‐ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. It is revealed that the original TiO 2 phase gets transformed to the anorthic Ti 7 O 13 and monoclinic K 2 Ti 4 O 9 phase after the first charge/discharge cycle, which further initiates the charge storage process via the conversion reactions.