Functional Role of Aramid Coated Separator for Dendrite Suppression in Lithium-Ion Batteries

The separator is an essential important key material in lithium-ion batteries (LIBs) because it is in contact with the positive and negative electrodes and the electrolyte. Aramid coated separators (ACS) are widely used in automotive and consumer batteries as high-performance separators for LIBs with high safety and excellent lifetime characteristics. Although much effort has been made to improve the electrolyte composition, the lithium deposition on the surface of the graphite electrode at low temperature and the high charge rate is still an unsolved problem in LIBs. In this work, lithium metal is used as a counter electrode, and a separator was placed between lithium metal and graphite composite electrode. The lithium was deposited on the surface of the graphite composite electrode through the separator. Then, the functional role of ACS in the initial deposition process was investigated. The dendrite blocking effect of ACS was studied by the observation of dendrite growth and pulse cycle performance.

One−Step Synthesis of Popcorn−Carbon/Co3O4 Composites as High−Performance Supercapacitor Electrodes

In this study, a novel assisted liquid−phase plasma electrolysis was developed to realize one−step synthesis of popcorn biomass−derived porous carbon/cobalt tetroxide (popcorn−carbon/Co3O4) composites, effectively improving the structural stability and conductivity of Co3O4. The phase structure, morphologies, chemical composition, and weight ratio of the as−prepared popcorn−carbon/Co3O4 composites were systematically analyzed. The results of X−ray diffraction (XRD), Raman spectrometer, Fourier infrared spectrometer (FTIR), X−ray photoelectron spectrometer (XPS), and thermogravimetry analyzer (TG) proved the synthesis of the popcorn−carbon/Co3O4 composites. Co3O4 nanoparticles were distributed relatively uniformly on the popcorn−carbon surface. The electrochemical properties of the popcorn−carbon/Co3O4 composite electrode materials were analyzed for exploring the influence of different Co/C ratios on the electrochemical properties of composites. The results showed that the popcorn−carbon/Co3O4 composite electrode materials prepared under 200:1 mass ratio of Co(NO3)2·6H2O and popcorn−carbon possessed a specific capacitance and specific capacity of almost 1264 F/g (594 C/g) at a current density of 1 A/g, exhibiting a better electrochemical property. The efficient, fast, and novel assisted liquid−phase plasma electrolysis provides a new method for the preparation of composite electrode materials on the supercapacitors.