Sur-/Interface Engineering of Hierarchical LiNi0.6Mn0.2Co0.2O2@LiCoPO4@Graphene Architectures as Promising High-Voltage Cathodes toward Advanced Li-Ion Batteries

Layered LiNi0.6Mn0.2Co0.2O2 (LNMC) cathode has attracted enormous attentions for Li-ion batteries thanks to its appealing combination of large capacity and desirable thermal stability. But it still suffers from repugnant phase distortion and serious capacity degradation upon cycling particularly with high cut-off voltages and elevated working temperatures. Herein, an efficient sur-/interface engineering strategy to finely fabricate hierarchical LNMC@LiCoPO4@graphene (LNMC@LCP@G) architectures is purposefully devised. Physicochemical characterizations comprehensively reveal that a uniform LCP nanoshell adheres tightly to the surface of bulk LNMC, and G sheets intersperse among LNMC@LCP microparticles as electron "bridge." By virtue of synergetic sur-/interface contributions from the multicomponents, the LNMC@LCP@G cathodes exhibit encouraging Li-storage behaviors including larger capacities, higher capacity retention, and better cycling performance with high upper cut-off voltage of 4.6 V both at 25 and 55 degrees C, and enhanced thermal stability in the delithiated state. More significantly, it is strongly believed that the electrode design concept here holds huge promise for smart synthesis of other advanced Ni-based cathodes for next-generation rechargeable lithium power batteries.