title: NASICON-Type Mg0.5Ti2(PO4)3Negative Electrode Material Exhibits Different Electrochemical Energy Storage Mechanisms in Na-Ion and Li-Ion Batteries.
abstract: A carbon-coated Mg0.5Ti2(PO4)3polyanion material was prepared by the sol-gel method and then studied as the negative electrode materials for lithium-ion and sodium-ion batteries. The material showed a specific capacity of 268.6 mAh g-1in the voltage window of 0.01-3.0 V vs Na+/Na0. Due to the fast diffusion of Na+in the NASICON framework, the material exhibited superior rate capability with a specific capacity of 94.4 mAh g-1at a current density of 5A g-1. Additionally, 99.1% capacity retention was achieved after 300 cycles, demonstrating excellent cycle stability. By comparison, Mg0.5Ti2(PO4)3delivered 629.2 mAh g-1in 0.01-3.0 V vs Li+/Li0, much higher than that of the sodium-ion cells. During the first discharge, the material decomposed to Ti/Mg nanoparticles, which were encapsulated in an amorphous SEI and Li3PO4matrix. Li+ions were stored in the Li3PO4matrix and the SEI film formed/decomposed in subsequent cycles, contributing to the large Li+capacity of Mg0.5Ti2(PO4)3. However, the lithium-ion cells exhibited inferior rate capability and cycle stability compared to the sodium-ion cells due to the sluggish electrochemical kinetics of the electrode.
authors.forename: Yingying
authors.initials: Y
authors.lastname: Zhao
authors.forename: Zhixuan
authors.initials: Z
authors.lastname: Wei
authors.forename: Qiang
authors.initials: Q
authors.lastname: Pang
authors.forename: Yingjin
authors.identifier: http://orcid.org/0000-0002-9375-9272
authors.initials: Y
authors.lastname: Wei
authors.affiliation: College of Science, Northeast Dianli University , Jilin 132012, P. R. China.
authors.forename: Yongmao
authors.initials: Y
authors.lastname: Cai
authors.affiliation: Institute for Applied Materials (IAM), Karlsruhe Institute of Technology (KIT) , D-76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Fu
authors.forename: Fei
authors.identifier: http://orcid.org/0000-0001-6413-0689
authors.initials: F
authors.lastname: Du
authors.affiliation: Institute for Applied Materials (IAM), Karlsruhe Institute of Technology (KIT) , D-76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Angelina
authors.initials: A
authors.lastname: Sarapulova
authors.affiliation: Institute for Applied Materials (IAM), Karlsruhe Institute of Technology (KIT) , D-76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Ehrenberg
authors.forename: Bingbing
authors.initials: B
authors.lastname: Liu
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
keywords: anode material; electrochemical properties; lithium ion battery; magnesium titanium phosphate; sodium ion battery