title: Large Polarization of Li4Ti5O12 Lithiated to 0 V at Large Charge/Discharge Rates.
abstract: The ability to enhance the specific capacity of Li4Ti5O12 (LTO) is of practical significance and offers the opportunity to increase the energy density of a full LTO-based battery. Widening the discharge cutoff voltage to 0 V is an effective way to increase the capacity of LTO at low current density. However, whether the specific capacity of LTO at large current rates can be enhanced remains largely unknown. Herein, intriguingly, we found that, when cycled down to 0 V (i.e., from 1.0-2.5 to 0-25 V), LTO exhibited greatly enhanced specific capacity at low rates (<5 C), while it showed a rapid capacity fading and a greatly increased charge/discharge potential gap at high rates (>10 C). The decreased lithium-ion diffusion caused by extra lithium-ion intercalation together with increased internal impedance significantly enhances the polarization and reduces the electrochemical reaction kinetics, which, in turn, hinders the lithiation reaction from LTO to Li7Ti5O12 and further to Li9Ti5O12.
authors.affiliation: Engineering Laboratory for Next Generation Power and Energy Storage Batteries, Engineering Laboratory for Functionalized Carbon Materials, Graduate School at Shenzhen, Tsinghua University , Shenzhen 518055, China.|Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University , Beijing 100084, China.|School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
authors.forename: Cuiping
authors.initials: C
authors.lastname: Han
authors.affiliation: Engineering Laboratory for Next Generation Power and Energy Storage Batteries, Engineering Laboratory for Functionalized Carbon Materials, Graduate School at Shenzhen, Tsinghua University , Shenzhen 518055, China.
authors.forename: Yan-Bing
authors.initials: YB
authors.lastname: He
authors.affiliation: Engineering Laboratory for Next Generation Power and Energy Storage Batteries, Engineering Laboratory for Functionalized Carbon Materials, Graduate School at Shenzhen, Tsinghua University , Shenzhen 518055, China.
authors.forename: Shuan
authors.initials: S
authors.lastname: Wang
authors.affiliation: Engineering Laboratory for Next Generation Power and Energy Storage Batteries, Engineering Laboratory for Functionalized Carbon Materials, Graduate School at Shenzhen, Tsinghua University , Shenzhen 518055, China.|Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University , Beijing 100084, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.affiliation: Engineering Laboratory for Next Generation Power and Energy Storage Batteries, Engineering Laboratory for Functionalized Carbon Materials, Graduate School at Shenzhen, Tsinghua University , Shenzhen 518055, China.
authors.forename: Hongda
authors.initials: H
authors.lastname: Du
authors.affiliation: Engineering Laboratory for Next Generation Power and Energy Storage Batteries, Engineering Laboratory for Functionalized Carbon Materials, Graduate School at Shenzhen, Tsinghua University , Shenzhen 518055, China.
authors.forename: Xianying
authors.initials: X
authors.lastname: Qin
authors.affiliation: School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
authors.forename: Zhiqun
authors.initials: Z
authors.lastname: Lin
authors.affiliation: Engineering Laboratory for Next Generation Power and Energy Storage Batteries, Engineering Laboratory for Functionalized Carbon Materials, Graduate School at Shenzhen, Tsinghua University , Shenzhen 518055, China.
authors.forename: Baohua
authors.initials: B
authors.lastname: Li
authors.affiliation: Engineering Laboratory for Next Generation Power and Energy Storage Batteries, Engineering Laboratory for Functionalized Carbon Materials, Graduate School at Shenzhen, Tsinghua University , Shenzhen 518055, China.|Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University , Beijing 100084, China.
authors.forename: Feiyu
authors.initials: F
authors.lastname: Kang
keywords: anode; batteries; capacity; enhancement; voltage range