Speaker: Filipp Obrezkov, Skolkovo Institute of Science and Technology, Center for Electrochemical Energy Storage, Russia.
Title: Ultrafast charging polyphenylamine-based cathode material for high rate lithium, sodium and potassium batteries
Abstract: We report the synthesis and investigation of a novel redox-active poly(N,N’-diphenyl-p-phenylenediamine) (PDPPD) polymer obtained via Buchwald-Hartwig C-N cross-coupling reaction. PDPPD has a high density of redox-active amine groups enabling the theoretical specific capacity of 209 mA h g-1, which is nearly twice higher compared to all other materials of this family reported so far. The obtained polymer was evaluated as a cathode material for dual-ion batteries and demonstrated promising operation voltages of 3.5-3.7 V and decent practical gravimetric capacities of 97, 94 and 63 mA h g-1 in lithium, sodium and potassium half-cells, respectively, while being tested at the moderate current density of 1C. A specific capacity of 84 mA h g-1 was obtained for the ultrafast lithium batteries operating at 100C (full charge and discharge takes 36 seconds only), which is, to the best of our knowledge, the highest battery capacity reported so far for such high current densities. The PDPPD//Li batteries also showed promising stability reflected in 67% capacity retention after 5000 cycles.
Speaker: Roman Kapaev, Skolkovo Institute of Science and Technology, Center for Electrochemical Energy Storage, Russia.
Title: Transition metal coordination polymers for metal-ion batteries
Abstract: Metal-organic polymers might be tuned to have high electrochemical capacity, high electron and ion conductivity and excellent cycling stability, which are necessary for the next generation of metal-ion batteries (MIBs) that are able to charge/discharge quickly over tens of thousands of cycles. In this report, synthesis and characterization of new classes of transition metal coordination polymers, which remain virtually unexplored as active materials for MIBs, are presented. In particular, metal-organic polymers derived from tetraaminobenzene, tetraaminobenzoquinone and dithiooxamide were studied. These compounds were shown to be promising as both ultrastable and ultrafast anode materials (>10 thousand cycles at >10 C) and cathode materials with high capacity and energy density (up to 350 mAh/g in 1.5-4.0 V vs. Li/Li+ range) in lithium- and sodium-ion batteries.
Date: December 12, 2018
Place: TPOC-3, Nobel str., 3, Blue Building, CEDL (4th floor, Room 450)