Te-vacancy-rich CoTe2_x anodes for efficient potassium-ion storage

Metal tellurides (MTes) have emerged as highly promising anode materials for potassium -ion batteries (PIBs) due to their exceptional volumetric capacity and superior electronic conductivity. The practical application of MTes, however, faces challenges such as slow kinetics, volumetric effects, and ill-defined shuttling phenomena of Kpolytellurides (K-pTex). Herein, we present a groundbreaking solution through the development of Te-vacancyrich CoTe2_x nanoparticles confined within a 3D honeycomb -like, hollow hierarchical gridded porous structured, S, N co -doped dual -carbon structural composite (CoTe2_x@3DPSNDC) via facile defect chemistry. This welldesigned composite offers an unparalleled combination of fast ion/electron transport and stable K-pTex, propelling battery reactions to new heights. State-of-the-art in -/ex -situ techniques and density functional theory calculations reveal the evolution and shuttling mechanism of K-pTex. Remarkably, our study validates the exceptional physical confinement and chemisorption capabilities of S, N co -doped dual -type carbon skeletons on K5Te3 and K2Te3, leading to ultra -stable potassium -ion storage. Furthermore, the Te vacancies substantially boost the intrinsic conductivity of CoTe2_x, resulting in accelerated reaction kinetics and enhanced rate performance of the CoTe2_x@3DPSNDC electrode which achieved an impressive capacity of 508.1 mAh cm_3 at 5.0 A g_ 1. Our advanced design concept provides unique insights into the construction of MTes anodes for achieving stable cyclability and fast -charging PIBs.