First Year Assessment de Venkata Sai, titulado “Nanoscale engineered electrode materials for high performance Lithium-ion batteries” – En la Sala de Seminarios a las 12:00 pm


Herein, highly ordered mesoporous pseudocapacitive electrodes for superior Li-ion storage are discussed. Hierarchical 1-D Co3O4nanorods of size ~20 nm with interfaces between the crystallites were synthesized using hydrothermal method followed by calcination. This 1D nanorods exhibited pseudocapacitive behavior with fast faradaic surface redox reactions utilizing the Li+ions from the interfaces. A predominated pseudocapacitance contribution of 80% of the total capacity through synergetic effect of the interfacial lithium storage along with excellent rate performance of the Co3O4 nanorods is reported. Co3O4nanorods with high discharge capacity of 1250 mAh/g at a charge-discharge rate of 50 mA/g and 840 mAh/g at 10A/g proved to be good anode for Li-ion storage. This material provides a specific discharge capacity of 980 mAh/g at 1A/g after 500 cycles with 62% capacity retention of the initial cycles. The nanorods outperformed as anode with surface charge storage mechanism than high surface area Co3O4nanoparticles. Post-cycling analysis demonstrated excellent structural stability assisting Co3O4nanorods as a stable and high performance anode for Li-ion battery.

Three dimensional (3D) hierarchical structured rGO embed with cobalt monoxide (CoO) nanoparticles exhibited an enhanced pseudocapacitive assisted Li ion storage. 3D CoO/N-rGO composite was synthesized by a simple solvothermal technique followed by carbonization. The 3-D morphology and network with N-doping maintains high surface area for providing effective electronic conductivity and increased the contact between electrode and electrolyte. These 3D design showed an extraordinary performance than the commercial Co3O4nanoparticles at 1A/g with 650 mAh/g for 1000 cycles. 3D CoO/N-rGO exhibited excellent electrochemical with 1050 mAh/g at current densities of 25mA/g and maintained 520 mAh/g even at 5A/g. The synergetic effect of the 3D morphology, an excellent pseudocapacitive contribution of 79% of the total capacity from the different interfacial storage phenomena was reported for the first time. Ex-situHRTEM showed that the 3-D morphology was retained after several charge-discharge cycles.