Effects of Ru doping on the structural stability and electrochemical properties of Li₂MoO₃ cathode materials for Li-ion batteries

Abstract

Li2MoO3 (LMO) material is one promising cathode material for lithium-ion batteries due to its high specific capacity and absence of oxygen release. However, the surface instability in air and the...

Ru-Doped Ni3Se4/NiSe/Nitrogen-Doped Carbon Nanotube Heterostructure for Lithium Storage

“…The pyrrole N could serve as electrochemically active sites for adsorbing Li + , and its content increase from 19.6% in Ru–Ni 3 Se 4 to 31.6% in Ru–Ni 3 Se 4 /NiSe@NC. Interestingly, the high-resolution Ru 3d spectrum (Figure h) is overlapped with the position of C 1s spectrum deconvoluted into three peaks, including C–C, C–N, and CC . The corresponding characteristic peaks of Ru 3d 5/2 and Ru 3d 3/2 are 280.2 and 284.0 eV, respectively, which verifies the presence of Ru 4+ in the biphasic heterostructure …”

“…Interestingly, the high-resolution Ru 3d spectrum (Figure 2h) is overlapped with the position of C 1s spectrum deconvoluted into three peaks, including C−C, C−N, and C�C. 23 The corresponding characteristic peaks of Ru 3d 5/2 and Ru 3d 3/2 are 280.2 and 284.0 eV, respectively, which verifies the presence of Ru 4+ in the biphasic heterostructure. 35 The lithium storage properties of Ru−Ni 3 Se 4 /NiSe@NC were further evaluated by galvanostatic and potentiostatic measurements.…”

“…22 He et al evidenced the excellent electrochemical properties of Rudoped Li 2 MoO 3 -based cathode materials for LIBs by density functional theory (DFT) calculations. 23 Further to the anode materials of LIBs, many heteroatom doping (Co, Fe, Ni, Mo, etc.) effects have also been extensively explored to improve the electrochemical performance of anode materials.…”

“…For example, Gao et al constructed Ru-doped LiFe 1– x Ru x PO 4 /C as cathode material for LIBs, delivering excellent specific capacity (162.6 mA h g –1 at 0.1 C) and long-life cycling performance . He et al evidenced the excellent electrochemical properties of Ru-doped Li 2 MoO 3 -based cathode materials for LIBs by density functional theory (DFT) calculations . Further to the anode materials of LIBs, many heteroatom doping (Co, Fe, Ni, Mo, etc.)…”

Crystallography of Active Particles Defining Battery Electrochemistry

“…Doping of the large ruthenium ion into an Li 2 MoO 3 cathode with a layered structure was shown, using HRTEM, to increase the lattice spacing in the (001) direction from 0.491 to 0.512 nm increasing the lithium ion diffusion co-efficient (D Li +) by 1 order of magnitude improving cell reversibility as capacity retention was increased from 76.5 to 125.2 mAh g −1 at 1C for 100 cycles. [160] A similar impact was observed with the doping of zirconium and fluoride ions into an NMC cathode to enhance cycling stability due to the increased bond strengths of Zr─O and F─O bonds; initial discharge capacity at 5 C was 40 mAh g −1 with a capacity retention 9.6% greater at a cycling rate of 2 C. Increased electrochemical performance was inferred from Rietveld refinement of XRD data as cation disorder was shown to be reduced, lattice regularity enhanced and c/a lattice parameter ratio increased highlighting the widening lithium ion diffusion channels. [31] An informed mineral choice enhancement (as in Figure 1) was carried out on a titanium doped lithiated cobalt phosphate (LiCo 0.9 Ti 0.05 PO 4 ) cathode; Ti 4+ ions were chosen as to minimize the formation of electrochemically inactive Co 3 O 4 and to create vacancies in Co sites within the olivine crystal structure to promote lithium-ion diffusion.…”