Micro-capacitor breakthrough

CHINESE scientists have constructed a prototype of planar sodium-ion microcapacitors with high power density, superior thermal stability and excellent mechanical flexibility.

The prototype was co-developed by two research groups led by Wu Zhongshuai from the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences, and Bao Xinhe, a CAS academic and president of the University of Science and Technology of China.

By coupling with a batterytype urchin-like sodium titanate anode and a capacitor-type nanoporous activated graphene cathode, the as-fabricated all-solid-state NIMCs working at 3.5 volts exhibited high volumetric energy density and an ultralow selfdischarge rate, according to the researchers.

Micro-capacitors and micro-batteries have been acknowledged as key power sources for miniaturized smart and integrated electronics, such as remote sensors, micro-robots and self-powered micro-systems.

The NIMCs assembled by DICP scientists would enjoy abundant sodium resources, low cost and electrochemical properties of sodium compared with lithium. While showing great potential for making flexible microelectronic devices, lithium’s massive applications will likely be snuffed out by limited supply and rising cost.

The micro-supercapacitors with multi-directional ion diffusion pathways and better capacitance and rate capability, hold great potential.

(Xinhua)