Multiply depolarized composite cathode of Li1.2Mn0.54Ni0.13Co0.13O2 embedded in a combinatory conductive network for lithium-ion battery with superior overall performances

The multiply depolarized composite cathode consisted of Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 (LMNCO) and a combinatory conductive network of graphene (GN) + carbon nanotubes (CNTs) in the active material and GN coating at the interface of current collector is synthesized via pasting LMNCO/GN/CNTs composite slurry on GN coated Al foil. The interlaced GN + CNTs conductive network improves both the electronic conductivity and Li ion transport and stabilizes the structure of composite. The GN coating at the interface of current/active materials interlaces with GN + CNTs in the active materials and improves the adhesion and reduces the resistance between the active material and current collector. Consequently, the LMNCO composite cathode exhibits superior rate capacities of 132 mAh g −1 at 5C and 97 mAh g −1 at 10C, high cycling capacity retentions of 86% at 1C and 85% at 2C after 100 cycles, respectively and lower voltage fading. This combinatory conductive network is much more efficient for reducing the resistance and polarization of electrode than any single conductive network of GN + CNTs, CNTs, GN or GN coating.