title: A Facile Bottom-Up Approach to Construct Hybrid Flexible Cathode Scaffold for High-Performance Lithium-Sulfur Batteries.
abstract: Lithium-sulfur batteries mostly suffer from the low utilization of sulfur, poor cycle life, and low rate performances. The prime factors that affect the performance are enormous volume change of the electrode, soluble intermediate product formation, poor electronic and ionic conductivity of S, and end discharge products (i.e., Li2S2and Li2S). The attractive way to mitigate these challenges underlying in the fabrication of a sulfur nanocomposite electrode consisting of different nanoparticles with distinct properties of lithium storage capability, mechanical reinforcement, and ionic as well as electronic conductivity leading to a mechanically robust and mixed conductive (ionic and electronic conductive) sulfur electrode. Herein, we report a novel bottom-up approach to synthesize a unique freestanding, flexible cathode scaffold made of porous reduced graphene oxide, nanosized sulfur, and Mn3O4nanoparticles, and all are three-dimensionally interconnected to each other by hybrid polyaniline/sodium alginate (PANI-SA) matrix to serve individual purposes. A capacity of 1098 mAh g-1is achieved against lithium after 200 cycles at a current rate of 2 A g-1with 97.6% of initial capacity at a same current rate, suggesting the extreme stability and cycling performance of such electrode. Interestingly, with the higher current density of 5 A g-1, the composite electrode exhibited an initial capacity of 1015 mA h g-1and retained 71% of the original capacity after 500 cycles. The in situ Raman study confirms the polysulfide absorption capability of Mn3O4. This work provides a new strategy to design a mechanically robust, mixed conductive nanocomposite electrode for high-performance lithium-sulfur batteries and a strategy that can be used to develop flexible large power storage devices.
authors.affiliation: Electrochemical Energy Laboratory, Department of Energy Science and Engineering, Indian Institute of Technology Bombay , Mumbai 400076, India.
authors.forename: Arnab
authors.initials: A
authors.lastname: Ghosh
authors.affiliation: Department of Inorganic and Physical Chemistry, Indian Institute of Science , Bangalore 560012, India.
authors.forename: Revanasiddappa
authors.initials: R
authors.lastname: Manjunatha
authors.affiliation: Department of Inorganic and Physical Chemistry, Indian Institute of Science , Bangalore 560012, India.
authors.forename: Rajat
authors.initials: R
authors.lastname: Kumar
authors.affiliation: Electrochemical Energy Laboratory, Department of Energy Science and Engineering, Indian Institute of Technology Bombay , Mumbai 400076, India.
authors.forename: Sagar
authors.initials: S
authors.lastname: Mitra
keywords: bottom-up approach; electrochemical performances; flexible cathode; in situ Raman spectroscopy; lithium−sulfur batteries