Ultrahigh-rate quasi-solid-state Zn-air batteries enabled by atomically dispersed Co site electrocatalyst and organhydrogel electrolyte

Quasi-solid-state Zn-air batteries (ZABs) have shown extraordinary promise for electrochemical energy storage, but are usually limited to relatively low-rate ability (< 10 mA cm−2), which caused by the sluggish O2 electrocatalysis and unstable electrochemical interface. Here we present an ultrahigh-rate and robust quasi-solid-state ZABs integrated with the atomic Co-N4 sites anchored on wrinkled nitrogen-doped graphene (Co SA-NDGs) cathode and the modulated H-bond network of polyacrylamide (PAM) organohydrogel electrolyte with. The quasi-solid-state ZABs exhibit the highest cycling rate of 100 mA cm−2 over 50 h at room temperature, which is nearly an order of magnitude higher than results reported previously. Meanwhile, the exceptional cycling stability more than 300 h (0.5 mA cm−2) with high-capacity retention at -60 oC and all-temperature adaptability (-60 to 60°C) are also demonstrated. The integral design towards high performance Zn-air batteries using atomic site catalyst and electrolyte with good interface stability broaden the scope of application.

A Flexible a-SiC-Based Neural Interface Utilizing Pyrolyzed-Photoresist Film (C) Active Sites

Carbon containing materials, such as graphene, carbon-nanotubes (CNT), and graphene oxide, have gained prominence as possible electrodes in implantable neural interfaces due to their excellent conductive properties. While carbon is a promising electrochemical interface, many fabrication processes are difficult to perform, leading to issues with large scale device production and overall repeatability. Here we demonstrate that carbon electrodes and traces constructed from pyrolyzed-photoresist-film (PPF) when combined with amorphous silicon carbide (a-SiC) insulation could be fabricated with repeatable processes which use tools easily available in most semiconductor facilities. Directly forming PPF on a-SiC simplified the fabrication process which eliminates noble metal evaporation/sputtering and lift-off processes on small features. PPF electrodes in oxygenated phosphate buffered solution at pH 7.4 demonstrated excellent electrochemical charge storage capacity (CSC) of 14.16 C/cm2, an impedance of 24.8 ± 0.4 kΩ, and phase angle of −35.9 ± 0.6° at 1 kHz with a 1.9 kµm2 recording site area.