Coexisting Fe single atoms and nanoparticles on hierarchically porous carbon for high-efficiency oxygen reduction reaction and Zn-air batteries.

Fe single-atom catalysts still suffer from unsatisfactory intrinsic activity and durability for oxygen reduction reaction (ORR). Herein, the coexisting Fe single atoms and nanoparticles on hierarchically porous carbon (denoted as Fe-FeN-C) are prepared via a Zn(OH)(CO)-assisted pyrolysis strategy. Theoretical calculation reveals that the Fe nanoparticles can optimize the electronic structures and d-band center of Fe active center, hence reducing the reaction energy barrier for enhancing intrinsic activity.

Polymer Electrolyte Glue: A Universal Interfacial Modification Strategy for All-Solid-State Li Batteries.

In recent years solid Li conductors with competitive ionic conductivity to those of liquid electrolytes have been reported. However, the incorporation of highly conductive solid electrolytes into the lithium-ion batteries is still very challenging mainly due to the high resistance existing at the solid-solid interfaces throughout the battery structure. Here, we demonstrated a universal interfacial modification strategy through coating a curable polymer-based glue electrolyte between the electrolyte and electrodes, aiming to address the poor solid-solid contact and thus decrease high interfacial resistance.

Porous covalent organic frameworks for high transference number polymer-based electrolytes.

While solid polymer electrolytes are poised to be the key component of next-generation solid-state batteries, the low Li+ transference number of the polymer electrolytes limits their practical applications. Here, porous boron-containing covalent organic frameworks with different surface areas were synthesized and employed as functional additives for enhancing the Li+ transference number of the polymer electrolytes. The boron-containing frameworks enable strong adsorption of the anions of the lithium salt, leading to a significantly enhanced Li+ transference number of the polymer electrolyte containing COF additives.

Cationic Covalent Organic Framework Nanosheets for Fast Li-Ion Conduction.

Covalent organic frameworks (COFs) with their porous structures that are accommodative of Li salts are considered to be potential candidates for solid-state fast Li conductors. However, Li salts simply infiltrated in the pores of solid-state COFs tend to be present in closely associate ion pairs, resulting in slow ionic diffusion dynamics. Here we incorporate cationic skeleton into the COF structure to split the Li salt ion pair through stronger dielectric screening.