High S Filling and Binder-Free Cathodes Enabled by Thick Arrayed Nanoframeworks and Subtle Interfacial Engineering

Besides tough kinetic issues in S cathodes, a poor S filling ratio, and a low compact density in films led by the overuse of porous hosts, conducting agents or other additives impede the further progress of Li-S cells. To overcome these constraints, we herein propose the rational design of robust NiO nanoframeworks to make high S filling and binder-free cathodes. Notably, such arrayed thick frameworks have an impressive spatial filling ability, showing a remarkable S filling ratio of 77.6%. To further optimize the cell behaviors, all of the arrayed NiO matrix surface is evenly paved by graphitic carbon shells, and the open-up architecture for S-filled frameworks is intactly encapsulated by functionalized nickel nitrate hydroxide layers. Thanks to subtle interfacial engineering and smart hybrid configurations, a high initial discharge capacity of over 1481 mAh g(-1) and a longer-term cyclic lifespan are achieved at 0.1 C. Also, this optimized binder-free cathode leads to great improvements in Coulumbic efficiency, the S utilization ratio, and rate capabilities. Our work presents not only an appealing route to making high S filling and binder-free cathodes for Li-S cells but also insight for the smart design of integrated film electrodes for other electrochemical applications.

Automated summary

This study proposes the rational design of robust NiO nanoframeworks to make high S filling and binder-free cathodes. Through subtle interfacial engineering and smart hybrid configurations, high initial discharge capacity, longer cyclic lifespan, and improved cell performance are achieved. This provides a valuable method for fabricating cathodes for Li-S cells and integrated film electrodes for other electrochemical applications.