Abstract
The highly reversible insertion/extraction of large-radius K+into electrode materials remains a tough goal,especially for conversion-type materials.Herein,we design a current collector-integrated electrode(N-CoSe/CoSe2-C@Cu)as an advanced anode for potassium-ion battery(PIBs).The conductive CoSe/CoSe2 heterojunction with rich Se vacancy defects,conductive sp2 N-doped carbon layer,and the elastic copper foil matrix can greatly accelerate the electron transfer and enhance the structural stability.Consequently,the well-designed N-CoSe/CoSe2-C@Cu current collector-integrated electrode displays enhanced potassium storage performance with regard to a high capacity(325.1 mAh·g-1 at 0.1 A·g-1 after 200 cycles),an exceptional rate capability(223.5 mAh·g-1 at 2000 mA·g-1),and an extraordinary long-term cycle sta-bility(a capacity fading of only 0.019％per cycle over 1200 cycles at 2000 mA·g-1).Impressively,ex situ scan-ning electron microscopy(SEM)characterizations prove that the elastic structure of copper foil is merged into the cleverly designed N-CoSe/CoSe2-C@Cu heterostructure,which buffers the deformation of structure and volume and greatly promotes the cycle life during the potassium/de-potassium process.
基金项目
National Natural Science Foundation of China(52371131)
Beijing Nova Program(Z211100002121082)
Interdisciplinary Research Project for Young Teachers of University of Science and Technology Beijing(FRF-IDRY-21-013)
Project of State Key Laboratory of Explosion Science and Technology(QNKT23-05)
Xiaomi Young Scholar Program()
万方数据