Effects of Ag-embedment on electronic and ionic conductivities of LiMnPO4 and its performance as a cathode for lithium-ion batteries. Issue 33 (17th July 2015)

• Record Type: Journal Article
• Authors: Lee, Kug-Seung; Lee, Kyung Jae; Kang, Yun Sik; Shin, Tae Joo; Sung, Yung-Eun; Ahn, Docheon
• Is Part Of: Nanoscale. Volume 7:Issue 33(2015)
• Page Start: 13860
• Page End: 13867
• Publication Date: 2015-07-17
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c5nr00933b
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : Formation of a conducting bridge structure and modification of atomic bond lengths of LiMnPO4 by Ag-embedment lead to greatly improved electrical and ionic conductivities and hence outstanding electrochemical performances. Abstract : An Ag-embedded LiMnPO4 (LMP) cathode was synthesized by solid-state reaction using a 1 wt% Ag precursor. Structure, morphology, and electrical conductivity studies of Ag-embedded LMP were performed by high resolution powder X-ray diffraction, high resolution transmission electron microscopy, energy dispersive X-ray spectroscopy, and four probe measurements. An Ag nanoparticle (∼26 nm) surrounded by several olivine crystallites within a single particle dramatically improved the overall electrical conductivity of LMP by four orders of magnitude relative to that of pristine LMP, playing roles as conducting bridges among LMP crystallites as well as particles. Rietveld analysis confirmed structural variations related to the modification of atomic bond lengths of Mn–O, P–O, and Li–O coordination due to Ag-embedment and thereby leads to facile Li ion diffusion in LMP. Consequently, although a small amount of Ag was included, the Ag-embedded LMP cathode exhibited outstanding electrochemical performances (92 mA h g −1 at 10 C) versus lithium.