Enhanced cycling properties of transition metal molybdates, Li x M2(MoO4)3 {0 ≤ x < 3} [M = Co,Ni]: a nanocomposite approach for lithium batteries

Abstract

Nanocomposite electrodes of recently identified polyanion cathode materials comprising Li x M 2 (MoO 4 ) 3 {0 ≤ x < 3} [M= Co, Ni] and nanosized carbon having 10 nm particle size were found to show remarkable improvement in their discharge capacity compared to the one prepared with acetylene black. The addition of nanosized carbon as a conductive additive offered improved initial discharge capacity of 121 mAh/g between 3.5-2.0 V vs Li/Li. The cause for such an increase could be firmly attributed to the filling up of the grain-grain contact area of the active material, facilitating the intimate grain-grain contacts in the composite structure leading to enhanced capacity delivery. As for the nanocomposite Li x Co 2 (MoO 4 ) 3 , it was found that at least 55% of its first discharge capacity was retained at the end of 20th cycle compared to its analogous counterpart, Li x Ni 2 (MoO 4 ) 3 .

Recent advances in the research of polyanion-type cathode materials for Li-ion batteries

“…All the studied materials showed very poor cycle stability due to the drastic structural changes accompanied by exponential capacity decay. After optimization by adding nanosized carbon as a conductive additive, Li 2 Co 2 (MoO 4 ) 3 exhibited an initial discharge capacity of 121 mAh/g with 55% retention after 20 cycles between 3.5-2 V. 227 For Co 2 (MoO 4 ) 3 , more than 2 Li p.f.u. can be inserted, corresponding to the Co 3+ /Co 2+ redox couple located at 2.6 V, and the irreversible Mo 6+ /Mo 5+ redox couple located at 2.2 V, respectively.…”

NASICON Open Framework Structured Transition Metal Oxides for Lithium Batteries

“…Comparison of first charge/discharge of nano-composite and conventional Li 2 M 2 (MoO 4 ) 3 against lithium between 4.9 and 1.5 V. . (Prabaharan et al, , 2007(Prabaharan et al, , 2008.…”