Enhanced reversibility and electrochemical performances of mechanically alloyed Cu3P achieved by Fe addition. Issue 32 (14th March 2016)

• Record Type: Journal Article
• Authors: Zhou, Aijun; Yang, Bin; Wang, Weihang; Dai, Xinyi; Zhao, Mingjuan; Xue, Jing; Han, Mangui; Fan, Cong; Li, Jingze
• Is Part Of: RSC advances. Volume 6:Issue 32(2016)
• Page Start: 26800
• Page End: 26808
• Publication Date: 2016-03-14
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra01637e
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Fe-addition into Cu3 P during mechanical alloying enhances the electrode's reversibility by a multi-phase constitute and a refined microstructure. Abstract : Cu3 P is a potential anode material for lithium-ion batteries with its comparable gravimetric capacity, but several times higher volumetric capacity (4732 mA h cm −3 ) than graphite. However, the cycling stability of Cu3 P is poor at low discharge potentials and high current densities. In this work, Fe addition is employed as a simple strategy to modulate the composition and phase constitution of Cu3 P nanopowders synthesized by wet mechanical alloying, and thereby to tune the electrochemical performance of the anode. The addition of Fe results in a composite constitute containing Cu3 P as the major phase and some other minor phases including Cu, α-Fe and FeP, which are combinationally determined by X-ray diffraction, energy dispersive X-ray spectroscopy and Mössbauer spectroscopy. Electrochemical tests reveal that both the cycling stability and the rate capability of the electrodes are improved by Fe addition. The Cu3 P electrode with 10% Fe addition shows the best cell performance, with the capacity being remarkably improved by over 100%, from 82 mA h g −1 to 178 mA h g −1 after 50 cycles at 0.75C between 2.0 V and 0.5 V vs. Li/Li + . The improvement of the electrochemical performance is engendered by a synergetic effect of the microstructure change of the powders and the presence of Fe-related minor phases, leading to increased electronic conductivity as well as enhanced electrochemical reversibility of the electrode.