title: Effect of Sodium-Site Doping on Enhancing the Lithium Storage Performance of Sodium Lithium Titanate.
abstract: Via Li(+), Cu(2+), Y(3+), Ce(4+), and Nb(5+) dopings, a series of Na-site-substituted Na1.9M0.1Li2Ti6O14 are prepared and evaluated as lithium storage host materials. Structural and electrochemical analyses suggest that Na-site substitution by high-valent metal ions can effectively enhance the ionic and electronic conductivities of Na2Li2Ti6O14. As a result, Cu(2+)-, Y(3+)-, Ce(4+)-, and Nb(5+)-doped samples reveal better electrochemical performance than bare Na2Li2Ti6O14, especially for Na1.9Nb0.1Li2Ti6O14, which can deliver the highest reversible charge capacity of 259.4 mAh g(-1) at 100 mA g(-1) among all samples. Even when cycled at higher rates, Na1.9Nb0.1Li2Ti6O14 still can maintain excellent lithium storage capability with the reversible charge capacities of 242.9 mAh g(-1) at 700 mA g(-1), 216.4 mAh g(-1) at 900 mA g(-1), and 190.5 mAh g(-1) at 1100 mA g(-1). In addition, ex situ and in situ observations demonstrate that the zero-strain characteristic should also be responsible for the outstanding lithium storage capability of Na1.9Nb0.1Li2Ti6O14. All of this evidence indicates that Na1.9Nb0.1Li2Ti6O14 is a high-performance anode material for rechargeable lithium ion batteries.
authors.affiliation: Faculty of Materials Science and Chemical Engineering, Ningbo University , Ningbo 315211, Zhejiang Province People's Republic of China.|School of Chemistry and Chemical Engineering, Anhui University of Technology , Maanshan 243002, Anhui Province People's Republic of China.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Wang
authors.affiliation: Faculty of Materials Science and Chemical Engineering, Ningbo University , Ningbo 315211, Zhejiang Province People's Republic of China.
authors.forename: Shangshu
authors.initials: S
authors.lastname: Qian
authors.affiliation: School of Chemistry and Chemical Engineering, Anhui University of Technology , Maanshan 243002, Anhui Province People's Republic of China.
authors.forename: Ting-Feng
authors.initials: TF
authors.lastname: Yi
authors.affiliation: Faculty of Materials Science and Chemical Engineering, Ningbo University , Ningbo 315211, Zhejiang Province People's Republic of China.
authors.forename: Haoxiang
authors.initials: H
authors.lastname: Yu
authors.affiliation: Faculty of Materials Science and Chemical Engineering, Ningbo University , Ningbo 315211, Zhejiang Province People's Republic of China.
authors.forename: Lei
authors.initials: L
authors.lastname: Yan
authors.affiliation: Faculty of Materials Science and Chemical Engineering, Ningbo University , Ningbo 315211, Zhejiang Province People's Republic of China.
authors.forename: Peng
authors.initials: P
authors.lastname: Li
authors.affiliation: Faculty of Materials Science and Chemical Engineering, Ningbo University , Ningbo 315211, Zhejiang Province People's Republic of China.
authors.forename: Xiaoting
authors.initials: X
authors.lastname: Lin
authors.affiliation: Faculty of Materials Science and Chemical Engineering, Ningbo University , Ningbo 315211, Zhejiang Province People's Republic of China.
authors.forename: Miao
authors.initials: M
authors.lastname: Shui
authors.affiliation: Faculty of Materials Science and Chemical Engineering, Ningbo University , Ningbo 315211, Zhejiang Province People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Shu
keywords: electrochemical property; lithium storage capability; sodium lithium titanate; sodium-site doping; structural evolution