Binder- and conductive additive-free laser-induced graphene/LiNi 1/3 Mn 1/3 Co 1/3 O 2 for advanced hybrid supercapacitors

Hybrid supercapacitors have recently emerged as next-generation energy storage devices that bridge the gap between supercapacitors and lithium-ion batteries. However, developing high energy cathodes that maintain long-term cycle stability and a high rate capability for real applications remains a significantly challenging issue. Herein, we report a facile synthesis method for a laser-scribed graphene/LiNi1/3Mn1/3Co1/3O2 (LSG/NMC) composite for high energy cathode materials for use in hybrid supercapacitors. LSG/NMC composites exhibit not only a high capacitance of up to 141.5 F/g but also an excellent capacitance retention of 98.1% after 1000 cycles at a high current density of 5.0 A/g. The introduction of an NMC spacer between the LSG layers provides an enlarged interspace that can act as an efficient channel for additional storage sites and rapid access. In addition, we further confirmed that hybrid supercapacitors using LSG/NMC cathodes and H2T12O25 anodes with an AlPO4/carbon hybrid coating layer (H-HTO) deliver a remarkable energy density of ~123.5 Wh/kg, power density of ~14074.8 W/kg, and a long-term cycle stability of 94.6% after 20,000 cycles. This work demonstrates that our proposed material can be considered a strong cathode candidate for next-generation hybrid supercapacitors. Graphene-based supercapacitors that use metal composites to enhance long-term stability and energy output have been created with the help of a DVD burner. Seung-Hwan Lee and Ki-Yong Kim from the University of Maryland in College Park, USA, and colleagues coated a DVD with graphene oxide and a mixture of lithium, nickel, cobalt, and manganese ions. By exposing the disc to the laser in a DVD burner, the team synthesized a material where graphene layers are separated by small amounts of the metal composite. This structure enables more of the graphene’s surface to be exposed for charge storage reactions, which are enhanced by the combination of metals. A prototype device delivered supercapacitor-level charging speeds and energy storage similar to a lithium-ion battery for over 20,000 cycles. In this work, we prepared laser-scribed graphene/LiNi1/3Mn1/3Co1/3O2 (LSG/NMC) without binder and conductive agent as a new breakthrough cathode through DVD burner. The obtained LSG/NMC delivers not only high capacitance but also rate capability and cyclability. This is because the NMC spacer maximizes the effective area of LSG. This work demonstrates that LSG/NMC cathode can be regarded as a candidate for high-performance hybrid supercapacitor.