Abstract
The continuous dependence on high-performance lithium-ion batteries leads to a pressing demand for advanced cathode materials of high energy density along with excellent cycling stability. Here we demonstrate a new concept of layered-rocksalt intergrown structure that harnesses the combined figures of merit from each individual phase, including the high capacity of layered and rocksalt phases, good kinetics of layered oxide and structural advantage of rocksalt phase. Based on this concept, lithium nickel ruthenium oxide of a main layered structure (R-3m) with intergrown rocksalt (Fm-3m) is developed, which delivers a high capacity with good rate performance. More importantly, the interwoven rocksalt structure successfully prevents the anisotropic structural change that is typical for the layered oxide, enabling a nearly zero-strain operation upon high-capacity cycling. Furthermore, a general design principle is successfully extrapolated and experimentally verified in a series of compositions. The success of such layered-rocksalt intergrown structure exemplifies a new concept of battery electrode design and opens up a vast space of compositions to develop high-performance intergrown cathodes for advanced energy storage devices.