Wide temperature range-and damage-tolerant microsupercapacitors from salt-tolerant, anti-freezing and self-healing organohydrogel via dynamic bonds modulation

The advance of microelectronics requires the micropower of microsupercapacitors(MSCs) to possess wide temperature-and damage-tolerance beyond high areal energy density.The properties of electrolyte are crucial for MSCs to meet the above requirements.Here,an organohydrogel electrolyte,featured with high salt tolerance,ultralow freezing point,and strong self-healing ability,is experimentally realized via modulating its inner dynamic bonds.Spectroscopic and theoretical analysis reveal that dimethyl sulfoxide has the ability to reconstruct Li^(+)solvation structure,and interact with free water and polyvinyl alcohol chains via forming hydrogen bonds.The organohydrogel electrolyte is employed to build MSCs,which show a boosted energy density,promising wide temperature range-and damage-tolerant ability.These attractive features make the designed organohydrogel electrolyte have great potential to advance MSCs.

Extremely low thermal conductivity from bismuth selenohalides with 1D soft crystal structure

Materials with intrinsically low thermal conductivity are of fundamental interests.Here we report a new sort of simple one-dimensional(1 D)crystal structured bismuth selenohalides(Bi Se X,X=Br,I)with extremely low thermal conductivity of^0.27 W m^-1K^-1 at 573 K.The mechanism of the extremely low thermal conductivity in 1 D Bi Se X is elucidated systematically using the first-principles calculations,neutron powder-diffraction measurements and temperature tunable aberration-corrected scanning transmission electron microscopy(STEM).Results reveal that the1 D structure of Bi Se X possesses unique soft bonding character,low phonon velocity,strong anharmonicity of both acoustic and optical phonon modes,and large off-center displacement of Bi and halogen atoms.Cooperatively,all these features contribute to the minimal phonon transport.These findings provide a novel selection rule to search low thermal conductivity materials with potential applications in thermoelectrics and thermal barrier coatings.