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Pure LiCoO2 nanopowders and those coated with lithium boron oxide (LBO) glass are prepared directly using high-temperature flame spray pyrolysis. Prior to post-treatment, the LiCoO2 powders with nanometer-size particles have low discharge capacities and poor cycle properties, irrespective of the amount of glass material. Post-treatment at 500 °C does not improve these properties significantly; however, the LBO glass-modified LiCoO2 powders post-treated at 600 and 700 °C demonstrates good cycle performance. The discharge capacity of the 5 wt% glass-modified LiCoO2 powders post-treated at 600 °C with a mean particle size of 120 nm, decreases from 122 to 109 mAh g−1 after 50 cycles, with a capacity retention of 89%. The capacity retentions of the pure and 2, 5, and 10 wt% glass-modified LiCoO2 powders post-treated at 700 °C are 86, 96, 98, and 98% after 50 cycles, respectively. [ABSTRACT FROM AUTHOR]

Abstract: Li2O–2B2O3 glass-modified LiMn2O4 cathode powders are prepared using spray pyrolysis. The powders with 1 and 5wt% glass material have a spherical shape, dense structure, and large grain size. The BET surface areas of LiMn2O4 powders with 0 and 1wt% glass material are 15.0 and 5.9m2 g−1, and their mean crystallite sizes are 29 and 49nm. The lithium boron oxide (LBO) glass material improves the cycle properties as well as the initial discharge capacities of the LiMn2O4 powders at a constant current density of 1C. The discharge capacity of LiMn2O4 powders without any glass material decreases from 116.3 to 92.6mAhg−1 after 100 cycles, the reduced capacity being 80% of the initial capacity. However, the discharge capacity of the LiMn2O4 powders with 1wt% glass material decreases from 131.0 to 113.2mAhg−1 after 100 cycles; thus, the capacity retention is 86% of the initial capacity. [Copyright &y& Elsevier]

Abstract: Spherically shaped vanadium pentoxide (V2O5) cathode powders with porous or dense morphologies are prepared directly via spray pyrolysis by varying the preparation temperatures between 600 and 1000°C. The powders prepared at 600°C consist of nanometer-sized rod-shaped crystals with porous structures. The V2O5 powders prepared at 1000°C have spherical shapes, clean surfaces, and dense structures, because of complete melting of the powders that occurs inside the hot-wall reactor. The Brunauer–Emmett–Teller (BET) surface areas of the V2O5 powders decrease from 24.7 to 3.2m2 g−1 when the preparation temperature increases from 600 to 1000°C. The V2O5 powders prepared at 1000°C have better cycle properties than those prepared at 600 and 800°C. The discharge capacity of the V2O5 powders prepared at 1000°C decreases from 432mAhg−1 to 263mAhg−1 after 20 cycles, in which the capacity retention is 61%. [Copyright &y& Elsevier]