Synthesize of porous LiNi_0.5Mn_1.5O₄ microcubes for lithium-ion battery and supercapacitor applications

Novel porous structured spinel LiNi_0.5Mn_1.5O₄ (LNMO) microcubes have been synthesized and applied as energy storage materials for Li-ion batteries and supercapacitors. These materials are excellent candidate to replace the existing LiMn₂O₄ used in the commercially available lithium-ion batteries. In this report, a systematic work has been performed to study the structural and electrochemical performance of the novel porous LNMO microcubes synthesized by facile precipitation routine. Structural stability of the porous LNMO microcubes was confirmed using thermogravimetric analysis and X-ray diffraction studies. Field emission scanning electron microscopic images revealed the LNMO microcubes were uniformly distributed with an average size of ~ 163 nm. Transmission electron microscopic images were confirmed the porous LNMO microcubes morphology and Brunauer–Emmett–Teller analysis showed the specific surface area of the synthesized LNMO, which was 36.42 m² g⁻¹ with an excellent pore volume of 3.62 cm³ g⁻¹ and an average pore size of 1.41 nm. Cyclic voltammetry, electrochemical impedance and charge–discharge studies were performed on the LiNi_0.5Mn_1.5O₄ to investigate the potential application of porous LNMO microcubes in lithium-ion battery and supercapacitors. As positive electrode in Li-ion cell, the porous LNMO microcubes exhibit an excellent discharge capacity of 138.4 mA h g⁻¹ at 1 C rate. The porous LNMO microcubes in supercapacitor was exhibited a maximum specific capacity of 294 F g⁻¹ at 0.75 A g⁻¹ with an excellent specific capacitance retention of 97% after 1000 cycles. The described porous LNMO microcubes are highly suitable electrode material for energy storage applications.