Effect of adsorption behaviour of polyelectrolytes on fluidity and packing ability of aqueous graphite slurries

Effects of the mixing sequence on the graphite dispersion and resistance of lithium-ion battery anodes

The performance of lithium-ion battery electrodes is influenced by particle dispersion in the slurry used for their production. In this study, we elucidate the effects and mechanism of the binder mixing sequence on the characteristics of the slurry used in the production of negative electrodes. Therefore, we optimize the preparation of the negative electrode slurry by evaluating the electrode characteristics resulting from changing the binder mixing sequence. During the preparation of the electrode slurry, the state of the adsorption of the binder to the particle changes when the sequence of binder addition is changed. The change in the adsorption state of the binder influences the particle dispersion in the slurry, rheological properties of the slurry, and packing characteristics of the particles. Under the influence of the aforementioned changes, electrodes possessing identical compositions exhibited different performances. The slurry in which the particles were dispersed produced an electrode possessing a low volume-resistivity, whereas the slurry in which the particles were agglomerated produced an electrode with a high volume-resistivity. Evidently, controlling the adsorption state of the binder by altering the binder mixing sequence is essential for fabricating electrodes possessing a low volume-resistivity.

A novel colloid composited with polyacrylate and nano ferrous sulfide and its efficiency and mechanism of removal of Cr(VI) from Water

Nano ferrous sulfide (n-FeS) colloids show an excellent performance in the application of remediation in situ soil and groundwater. However, due to the interfacial effect and high reactivity of the nano sized FeS, n-FeS easy to agglomerate, which reduces their remediation efficiency. In this study, a novel composite colloid was synthesized using polyacrylic acid salt (PAA) and n-FeS. The PAA-n-FeS colloid was used to remove Cr(VI) in water remediation, and its removal mechanism and efficiency were explored. The results showed that the hydrodynamic diameter of PAA-n-FeS ranged from 65.04-90.09 nm and the zeta potential was from -27 to -54 mV at pH varying from 4.5-9.0. PAA was coated on the surface of n-FeS, which improved the dispersibility and stability of n-FeS by increasing the steric hindrance and electrostatic repulsion between n-FeS particles. Moreover, the Cr(VI) maximum removal amount PAA-n-FeS was 432.79 mg/g, which was significantly higher than that of n-FeS (218.29 mg/g) and PAA (12.32 mg/g). The mechanism of PAA-n-FeS removal of Cr(VI) was mainly derived from its own reducibility. The reaction products were mainly Cr(OH)₃, Cr(III)-Fe(III), Cr₂O₃, and Cr₂S₃. This research not only finds a new stabilizer for preventing n-FeS agglomeration, but also provides a novel n-FeS composited colloid for promoting the practical application to Cr(VI) removal from water.