Vanadium pentoxide (V2O5) nanoparticles (30–60 nm) were made by a one-step and scalable flame spray pyrolysis (FSP) process. Optimization of the FSP processing conditions (precursor concentration and injection rate) enhanced the electrochemical performance of these nanoparticles. Increasing the cut-off potential for discharging from 1.5 to 2.5 V vs. Li/Li+ improved the cycle life of these V2O5 nanoparticles. Particles with the lowest specific surface area (∼32 m2 g−1) and highest phase purity (up to 98 wt%) showed excellent cyclability between 2.5 and 4.0 V vs. Li/Li+, retaining a specific charge of 110 mAh g−1 beyond 100 cycles at a specific current of 100 mA g−1, and also superior specific charge of 100 mAh g−1 at specific current up to 20C rate (or 2000 mA g−1).
27 February 2014 in Journal of Materials Chemistry A
Among the layered transition metal oxide electrodes, the NCA (Li(Ni1−x−yCoxAly)O2) and the NMC (Li1+a(NixMnyCoz)1−aO2) families with working potentials ranging from 4 V to close to 5 V against Li metal are nowadays identified as potential high specific energy materials. The present candidates have their advantages and drawbacks, i.e. NCA is a high energy density material but safety is of major concern while NMC has a lower energy density but exhibits improved safety. Recently, overlithiated layered transition metal oxides have proved to deliver reversible specific charge over 200 mA h g−1. The high specific charge is associated with a complex reaction mechanism that involves the activation of the material at high potentials. However, further R&D is needed for the current technology to meet the needs, in terms of safety, cost, energy and power capabilities, of the emerging HEV and EV market. A review of the state-of-the-art of these families of compounds together with current approaches for their future development is presented.
6 March 2020 in ACS Applied Materials & Interfaces