Pomegranate-like C@TiO2 mesoporous honeycomb spheres for high performance lithium ion batteries

Constructing metal-organic framework-derived Mn2O3multishelled hollow nanospheres for high-performance cathode of aqueous zinc-ion batteries

Herein, we successfully synthesize Mn₂O₃multishelled hollow nanospheres through simply oxidizing Mn-based metal-organic framework microspheres. The number of the shells reaches 4. Many cavities and nanograins are hidden underneath the shell. The multishelled hollow structure brings about a wide hierarchical mesopore size range, large pore volume (0.26 cm³g^-1) and high specific surface area (117.6 m²g^-1). The superior zinc-ion storage performance may be achieved. The reversible capacity reaches 453 mAh g^-1at current density of 0.1 A g^-1. After 500 cycles at 1 A g^-1, the discharge capacity of 152.8 mAh g^-1is still delivered. The discharge capacity at 1.5 A g^-1stabilizes at 107 mAh g^-1. The zinc storage process is further studied through kinetics analyses. It is found that in the zinc storage process, ion diffusion process and capacitive process occur simultaneously, and the capacitive process is dominant. The excellent electrochemical performance is mainly attributed to the multishelled hollow nanosphere structure of Mn₂O₃. This structure promotes contact of electrode materials/electrolyte, offers more active sites, facilitates infiltration of electrolyte, buffer volume change of Mn₂O₃, improving electrochemical activity, reaction kinetics and cycling performance of Mn₂O₃. Overall, Mn₂O₃multishelled hollow nanosphere is an excellent cathode material for aqueous zinc-ion batteries.

Intrinsically conducting polymers and their combinations with redox-active molecules for rechargeable battery electrodes: an update

Intrinsically conducting polymers and their copolymers and composites with redox-active organic molecules prepared by chemical as well as electrochemical polymerization may yield active masses without additional binder and conducting agents for secondary battery electrodes possibly utilizing the advantageous properties of both constituents are discussed. Beyond these possibilities these polymers have found many applications and functions for various further purposes in secondary batteries, as binders, as protective coatings limiting active material corrosion, unwanted dissolution of active mass ingredients or migration of electrode reaction participants. Selected highlights from this rapidly developing and very diverse field are presented. Possible developments and future directions are outlined.