Affiliation:
1. College of Materials Science and Engineering Zhejiang University of Technology Hangzhou 310014 China
2. Quzhou Institute of Power Battery and Grid Energy Storage Quzhou 324000 China
3. College of Chemical and Biological Engineering Zhejiang University Hangzhou 310027 China
Abstract
AbstractAnode‐free sodium metal battery (AFSMB) promises high energy density but suffers from the difficulty of maintaining high cycling stability. Nonuniform sodium (Na) deposition on the current collector is largely responsible for capacity decay in the cycling process of AFSMB. Here, a unique copper phosphide (Cu3P) nanowire is constructed on copper (Cu3P@Cu) as a sodium deposition substrate by an in situ growth method. Superior electrochemical performance of Cu3P@Cu anode is delivered in asymmetric cells with an average Coulombic efficiency of 99.8% for over 800 cycles at 1 mA cm−2 with 1 mA h cm−2. The symmetric cell of Cu3P@Cu displayed a cycling lifespan of over 2000 h at 2 mA cm−2 with 1 mA h cm−2. Cryo‐transmission electron microscope characterization and first principles calculation revealed that the low Na+ absorption energy and low Na+ diffusion energy barrier on Na3P promoted uniform Na nucleation and deposition, thus enhancing the Na surface stability. Moreover, anode‐free Na3V2(PO4)3//Cu3P@Cu full pouch cell delivered a considerable cycling capacity of ≈15 mA h in 170 cycles, demonstrating its practical feasibility.
Funder
National Natural Science Foundation of China
Subject
Mechanical Engineering,Mechanics of Materials,General Materials Science