Rational material design of Li-excess metal oxides with disordered rock salt structure

Zero-Strain Cathodes for Lithium-Based Rechargeable Batteries: A Comprehensive Review

“…As reviewed above, several zero-strain cathode materials have adopted spinel structures with a relatively stable framework, but the disordered rock salt structure has also received significant attention as a novel zero-strain material. The disordered rock salt structure possesses the advantages of delivering a high capacity and undergoing minimal isotropic lattice change. − Li et al designed Li 1.2 Ni 0.4 Ru 0.4 O 2 as a mixture of layered structures and rock salt nanodomains to integrate the advantages of the high capacity of rock salt and layered structure, high rate capability of layered oxide, and isotropic structural change of the rock salt. The synthesized Li 1.2 Ni 0.4 Ru 0.4 O 2 was primarily composed of a layered structure (70 mol % R m ) and minor rock-salt nanodomains (30 mol % Fmm) (Figure d).…”

Li trapping in nanolayers of cation ‘disordered’ rock salt cathodes

“…3 DRS offers a tantalizing promise for high-energy-density Li-ion batteries with capacities beyond 300 mA h g À1 , low percolation energies of 3D Li-diffusion paths and absence of phase transformations during cycling. 4,5 In a recent study we identied an improved electrochemical performance of a nanostructured Li 2 MnO 3 (nano-Li 2 MnO 3 ) DRS cathode material displaying reversible capacities of 290 mA h g À1 for over 10 cycles; 6 whilst its crystalline counterpart, the well-researched Li 2 MnO 3 , displays a 50% capacity drop over the rst ve cycles. 7 A joint neutron and X-ray total scattering approach evidenced a phase transformation during a high energy ball milling process, where Li 2 MnO 3 synthesized at 900 C with a layered structure (C2/m) transformed into a nanostructured and disordered cubic MnO-type rock salt (Fm 3m).…”

“…3 DRS offers a tantalizing promise for high-energy-density Li-ion batteries with capacities beyond 300 mA h g −1 , low percolation energies of 3D Li-diffusion paths and absence of phase transformations during cycling. 4,5…”

Nanoscale domain imaging of Li-rich disordered rocksalt-type cathode materials with X-ray spectroscopic ptychography

“…Li-rich metastable cathode materials have recently been attracting attention for the development of the cathode materials that satisfying the requirements. In Li-rich disordered rocksalt (DRS)-type cathode materials (Li x TM 2-x O 2 , x>1.1 TM: transition metal elements; e.g., V, Ti, Mn, Nb, Cr, Mo), Li and TM randomly occupy the same site [1][2][3][4][5][6][7] . They achieve a higher reversible capacity than conventional layered rocksalt type cathode active materials such as commercial LiCoO 2 and Li-Ni-Mn-Co-O 2 compounds 1 .…”

“…MM is a simple and powerful approach to obtaining metastable, amorphous, nanocomposite, and nanosized particles by mixing and crushing powders 9 . It is expected that the reversible capacity and rate capability can be increased by reducing the particle size to the nanoscale by MM 4 . Note that MM is a physical mixing process; hence, there are chemical and structural heterogeneities in the synthesized materials.…”