Polyvinylpyrrolidone assisted sol–gel route LiCo1/3Mn1/3Ni1/3PO4 composite cathode for aqueous rechargeable battery

Abstract

Kandhasamy, S., Pandey, A. and Minakshi, M. (2012)Polyvinylpyrrolidone assisted sol-gel route LiCo1/3Mn1/3Ni1/3PO4 composite cathode for aqueous rechargeable battery. Electrochimica Acta, 60 (15 Jan This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. polymer assisted sol-gel (SG) methods, is reported as a cathode material for aqueous rechargeable batteries. X-ray diffraction (XRD) analysis confirms phase pure compounds in an orthorhombic structure for both these methods. However, microstructural images show polyvinylpyrrolidone (PVP) assisted SG method aids colloidal growth giving evenly distributed microparticles while SS method tend to an agglomeration during high-temperature processing.The electrochemical properties for SG are seen to be dramatically superior to those of SS. The galvanostatic analysis of the SG shows improved specific capacity over the initial cycles (45 mAh/g and 60 mAh/g for the 1 st and 20 th cycles) and stabilized upon cycling. This unique capability is due to the trapped organic products from the thermal decomposition of PVP that facilitates Li + transfer. The trapped organic coating on the cathode surface without affecting the bulk olivine is evidenced by XRD, FTIR and XPS spectroscopic techniques.

Olivine-type cathode for rechargeable batteries: Role of chelating agents

“…Also, Sasaki et al [25] reported that the trapped organic between electrode-electrolyte interface increase the lithium ion diffusion rate with better capacity retention. The direct evidences of trapped polymer layer formations in PVP are reported by the authors in a separate publication [26]. On the other hand, chelating agents CA (from 40 to 30 mAh/g) and TEA (from 68 to 38 mAh/g) cathodes showed drastic loss of 23 % and 45 % in their capacities respectively on subsequent cycles.…”

Role of structural defects in olivine cathodes

“…To investigate the role of synthesis in forming structural defects, we synthesized our cathode (LiCo 1/3 Ni 1/3 Mn 1/3 PO 4 ) by sol-gel synthesis using different chelating agents. The x-ray diffraction patterns (XRD) of triethanolamine (TEA) and polyvinylpyrrolidone (PVP) [36] assisted sol-gel synthesized materials are shown in Fig. 4.…”

Synthetic strategies for better battery performance through advances in materials and chemistry: Olivine LiMn1/3Co1/3Ni1/3PO4

“…All the samples presented a relatively dense structure (free from voids) though some micro-structural differences can be identified. It is reported earlier [23] that the solid state synthesized sample is not homogenous with irregular particle sizes and well separated grains compared to that of wet chemistry route (presented here). The sol-gel product (Fig.…”