@article {48356, title = {Influence of ice templating on oxygen reduction catalytic activity of metal-free heteroatom-doped mesoporous carbon derived from polypyrrole for zinc-air batteries}, journal = {Energy Technology}, volume = {10}, year = {2022}, month = {DEC}, type = {Article}, abstract = {

The development of highly active, cost-effective, and durable, noble metal-free oxygen reduction electrocatalysts is inevitable for the full-fledged implementation of fuel cells and zinc-air batteries. This work reports the synthesis of heteroatom (N, P, S)-doped metal-free mesoporous carbon-based electrocatalyst derived from polypyrrole by combining the ice templating, freeze-drying, and carbonization processes. The correlation between the structure and electrochemical activity of the polypyrrole-derived carbon-based electrocatalyst in the presence and absence of ice templating is investigated. The optimized electrocatalyst, aided by the ice-templating and freeze-drying step, shows an onset and half-wave potential (E-1/2) of 0.94 and 0.78 V vs reversible hydrogen electrode, respectively, in an alkaline electrolyte (0.1 m KOH). Later, the application of the optimized electrocatalyst is demonstrated in a primary zinc-air battery (ZAB) cell. The results prove that the ZAB device performance based on the homemade catalyst is on par with that of the state-of-the-art Pt/C cathode. The catalyst performance is correlated with the heteroatom doping and the enhanced porosity of the sample benefitted from ice templating. Ultimately, this work depicts a facile and rational synthesis of a truly metal-free electrocatalyst for the primary ZABs that can be a potential replacement for state-of-the-art systems.

}, keywords = {metal-free electrocatalysts, oxygen reduction reaction, zinc-air batteries}, issn = {2194-4288}, doi = {10.1002/ente.202200840}, author = {Kurian, Maria and Ghosh, Meena and Vijayakumar, Vidyanand and Puthiyaveetil, Priyanka Pandinhare and Torris, Arun and Kurungot, Sreekumar} } @article {48692, title = {Binder-free and flexible VOPO4/CNT film as cathode for aqueous rechargeable Zn-metal battery}, journal = {Advanced Sustainable Systems}, volume = {7}, year = {2023}, month = {SEP}, type = {Article}, abstract = {

Aqueous rechargeable Zn-metal batteries (AZMBs) are promising energy storage aids due to their inherent safety, low cost, and competent performance, with prospects in stationary and portable applications. In this regard, one of the critical requirements is developing electrodes that can adapt to mechanical deformation without compromising the charge storage performance. The current work demonstrates the development of a binder-free and mechanically flexible composite cathode film (VP/fCNT-F, where {\textquoteleft}F{\textquoteright} stands for the film) based on VOPO4 (VP) and functionalized carbon nanotubes (fCNTs). The VP/fCNT-F film processing involves simple vacuum filtration of the composite obtained from the in-situ reaction of the fCNTs and the VP precursor in an aqueous medium. The functionalization of carbon nanotube (CNT) is important for the homogenous dispersion of VP and fCNT. The VP/fCNT-F electrode is used as a monolithic electrode in AZMB cells in combination with both liquid and quasi-solid-state gel polymer electrolytes. Besides, the utility of the VP/fCNT-F electrode in a flexible battery configuration is also demonstrated. Interestingly, in both the coin-cell and flexible configurations, the VP/fCNT-F electrode delivers a comparable discharge capacity of 90 and 78 mAh g(-1), respectively (at 0.1 A g(-1)), validating the advantage of the binder-free VP/fCNT-F electrode for AZMBs.

}, keywords = {binder-free cathodes, flexible batteries, layered VOPO4, polymer gel electrolytes, self-standing flexible films}, issn = {2366-7486}, doi = {10.1002/adsu.202300141}, author = {Dilwale, Swati and Babu, Athira and Puthiyaveetil, Priyanka Pandinhare and Kurian, Maria and Ghosh, Meena and Kurungot, Sreekumar} } @article {48734, title = {Donor-acceptor-based two-dimensional polymer as a supercapacitor electrode with long cycling stability}, journal = {New Journal of Chemistry}, volume = {47}, year = {2023}, month = {OCT }, pages = {18049-18054}, type = {Article}, abstract = {

The high demand for energy and energy-storage devices urged organic 2D polymers as a potential candidate in this area. One of the major attractions of 2D polymers in electrochemical applications is their long cycling stability due to their rigid and porous structure. Herein, we developed a 2D polymer comprised of donor-acceptor units exhibiting reasonably good performance as a supercapacitor. The 2D polymer displayed a maximum specific capacitance of 218 F g-1 at a current rate of 0.1 A g-1, a higher power density of 4648.35 W kg-1, and an energy density of 7.05 W h kg-1. In a cycling stability test, it demonstrated a capacitance retention of 70\% over 10 000 continuous charge-discharge cycles at a current rate of 2.5 A g-1. Such long cycling stability was attributed to the donor-acceptor units and the crystalline nature of the polymer. The sensible selection of the building blocks of the 2D polymers is crucial for the performance and hence provides scope for improvement. An organic donor-acceptor-based 2D polymer, a promising candidate for energy storage devices, displays a specific capacitance of 218 F g-1, a power density of 4648.35 W kg-1, an energy density of 7.05 W h kg-1, and a capacitance retention of 70\% over 10 000 cycles.

}, issn = {1144-0546}, doi = {10.1039/d3nj02510a}, author = {Bhagyasree, T. M. and Puthiyaveetil, Priyanka Pandinhare and Kumar, Viksit and Asokan, Kiran and Sreekumar, K. and Babu, Sukumaran Santhosh} }