Journal:Energy & Environmental Science
Abstract:The current exploration of high-energy-density cathode materials for Li-ion batteries is mainly
concentrated on either so-called “Li-rich” or “Ni-rich” oxides. However, both are suffering from
formidable practical challenges. Here, we combine these two concepts to obtain ‘‘Li-rich Ni-rich’’ oxides
in pursuit of more practical high-energy-density cathodes. As a proof of concept, we synthesized an
array of Li1+yNi(35y)/3Mo2y/3O2 oxides, whose structures were identified to be the coexistence of LiNiO2-
rich and Li4MoO5-rich domains with the aid of XRD, TEM, and NMR techniques. Such an intergrowth
structure of 5–20 nm size enables excellent mechanical and structural reversibility for the layered rocksalt
LiNiO2-rich domain upon cycling thanks to the robust cubic rock-salt Li4MoO5-rich domain
enabling an ‘‘epitaxial stabilization’’ effect. As a result, we achieved high capacities (4220 mA h g1) with
Ni contents as low as 80%; the Li1.09Ni0.85Mo0.06O2 member (y = 0.09) shows much improved cycling
performances (91% capacity retention for 100 cycles at C/10) compared with pure LiNiO2. This work
validates the feasibility of constructing Li-rich Ni-rich compounds in the form of intergrowing domains
and hence unlocks vast possibilities for future cathode design.
Volume:16
Journal:https://pubs.rsc.org/en/content/articlelanding/2008/zo/d2ee03969a/unauth