Reducing the Charge Carrier Transport Barrier in Functionally Layer-Graded Electrodes

Yanyan Zhang; Oleksandr I Malyi; Yuxin Tang; Jiaqi Wei; Zhiqiang Zhu; Huarong Xia; Wenlong Li; Jia Guo; Xinran Zhou; Zhong Chen; Clas Persson; Xiaodong Chen

doi:10.1002/anie.201707883

Reducing the Charge Carrier Transport Barrier in Functionally Layer-Graded Electrodes

Angew Chem Int Ed Engl. 2017 Nov 20;56(47):14847-14852. doi: 10.1002/anie.201707883. Epub 2017 Oct 20.

Authors

Affiliations

¹ Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
² Centre for Materials Science and Nanotechnology, Department of Physics, University of Oslo, P.O. Box 1048 Blindern, NO-0316, Oslo, Norway.

PMID: 28960725
DOI: 10.1002/anie.201707883

Abstract

Lithium-ion batteries (LIBs) are primary energy storage devices to power consumer electronics and electric vehicles, but their capacity is dramatically decreased at ultrahigh charging/discharging rates. This mainly originates from a high Li-ion/electron transport barrier within a traditional electrode, resulting in reaction polarization issues. To address this limitation, a functionally layer-graded electrode was designed and fabricated to decrease the charge carrier transport barrier within the electrode. As a proof-of-concept, functionally layer-graded electrodes composing of TiO₂ (B) and reduced graphene oxide (RGO) exhibit a remarkable capacity of 128 mAh g^-1 at a high charging/discharging rate of 20 C (6.7 A g^-1 ), which is much higher than that of a traditionally homogeneous electrode (74 mAh g^-1 ) with the same composition. This is evidenced by the improvement of effective Li ion diffusivity as well as electronic conductivity in the functionally layer-graded electrodes.

Keywords: TiO2(B); charge carrier barrier; functionally graded electrodes; high charging rates; lithium-ion batteries.

Publication types

Research Support, Non-U.S. Gov't