Chinese scientists have constructed a prototype of planar sodium-ion microcapacitors (NIMCs) with high power density, superior thermal stability and excellent mechanical flexibility.
The prototype was co-developed by two research groups respectively led by Wu Zhongshuai from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), and Bao Xinhe, a CAS academician and president of the University of Science and Technology of China.
By coupling with a battery-type urchin-like sodium titanate anode and a capacitor-type nanoporous activated graphene cathode, the as-fabricated all-solid-state NIMCs working at 3.5 V exhibited high volumetric energy density and an ultralow self-discharge rate, according to the researchers.
Microcapacitors and microbatteries have been acknowledged as key power sources for miniaturized smart and integrated electronics, such as remote sensors, microrobots and self-powered microsystems.
The NIMCs assembled by DICP scientists would enjoy abundant sodium resources, low cost and electrochemical properties of sodium comparable to lithium. While showing great potential for making flexible microelectronic devices, lithium's massive applications, however, will likely be snuffed out by the limited supply and rising cost of the resource.
The micro-supercapacitors with multi-directional ion diffusion pathways and better capacitance and rate capability, hold tremendous potential for microelectronics, researchers said.
A paper on the results of the research was published in the journal Advanced Science.