In situ growth-optimized synthesize of Al-MOF@RGO anode materials with long-life capacity-enhanced lithium-ion storage

Abstract

Low lithium ions transport capacity, poor electronic conductivity and the structural stability of metal organic frameworks (MOFs) severely restrict the development of practical lithium-ion batteries (LIBs). Therefore, many researchers were motivated to conduct investigations from the direction of both pore size regulation and composite synthesize for MOF-based materials. In the present work, the Al-MOF (Al(OH)[O2C-C6H4-CO2]) particles with well-developed pore structures were conceived. They were optimized by adjusting the hydrothermal self-assembly reaction time and temperature, particularly when the pore size increased from micropores to mesopores, which greatly improves the transport capacity of lithium ions. Then, the in-situ growth-optimized Al-MOF particles on the reduced graphene oxide (RGO) layer can effectively improve electronic conductivity and structural stability through the dual regulation of electrostatic attraction and heterogeneous nucleation. The RGO-supported Al-MOF@RGO anode used in LIBs exhibits a specific capacity of 468.5 mAh/g after 1000 cycles at a current density of 1.0 A/g. The specific capacity of the Al-MOF@RGO anode is still as high as 282.0 mAh/g after 1000 cycles even at 2.0 A/g. As expected, the in-situ growth-optimized synthesize of the Al-MOF@RGO anode with a long-life capacity-enhanced trend shows superior lithium storage performance. The Al-MOF@RGO//LiFePO4 full cell measurement demonstrates its potential of commercial applications in LIBs.