High nickel layered oxide LiNi0.8Mn0.1Co0.1O2 (NMC811) was coated with a nanometer layer coating of a lithium ion conducting solid electrolyte, lithium phosphorus oxynitride (LiPON) by using RF-magnetron sputtering. The cells with LiPON coated NMC811 exhibit much improved cycling performance compared to the cells with pristine NMC811 with 64.1% and 42.6% capacity retention respectively over 100 cycles in an all solid-state battery. The LiPON layer provides interfacial stability at high voltages, suppresses the growth of impedance with cycling and improves the rate capability. Thicker coatings show a negative impact on the performance owing to the increase in electronic resistance with increasing thickness of the LiPON layer. The dQ/dV analysis, electrochemical impedance spectroscopy (EIS), and the overpotential study during galvanostatic cycling were conducted to elucidate the improvement of the cycling stability and enhancement of Li+ transport through LiPON layers surrounding NMC811.

The aim of this study was to investigate the effects of plasma-enhanced deposition of an organosilane and benzene on resin bonding to a dental zirconia ceramic. A total of 70 zirconia specimens, which were polished before sintering, were randomly divided into five groups according to surface treatments before applying a dental adhesive (each group, n = 14): group 1, no previous treatment (control); group 2, plasma deposition with tetramethylsilane (TMS); group 3, plasma deposition with benzene; group 4, sequential plasma deposition with TMS and benzene; and group 5, a zirconia primer (Z-Prime Plus). A dental adhesive (Scotchbond Multi-Purpose adhesive) was applied to the surface-treated zirconia, and resin composite rods were built in to enable shear bond-strength testing. The sequential deposition of TMS and benzene showed the highest bond strength [22.7 ± 3.7 MPa (mean ± SD)], approximately twice that of Z-Prime Plus (10.3 ± 3.2 MPa). The plasma deposition with either TMS or benzene also significantly improved bond-strength values compared with the negative-control group, and their effects were not statistically different from that of Z-Prime Plus. Following plasma deposition with TMS, the introduction of silicon-oxygen-zirconium (Si-O-Zr) bonds on the zirconia surface was confirmed via X-ray photoelectron spectroscopy (XPS) analysis. Transmission electron microscopy and energy dispersive X-ray spectroscopy showed that a silica-like layer and a polymerizable carbon-rich layer were formed through sequential deposition with TMS and benzene.

Silicon (Si)-based anode materials can increase the energy density of lithium (Li)-ion batteries owing to the high weight and volume capacity of Si. However, their electrochemical properties rapidly deteriorate due to large volume changes in the electrode resulting from repeated charging and discharging. In this study, we manufactured structurally stable Fe–Si alloy powders by performing high-energy milling for up to 24 h through the reduction of the Si phase size and the formation of the α-FeSi2 phase. The cause behind the deterioration of the electrochemical properties of the Fe–Si alloy powder produced by over-milling (milling for an increased time) was investigated. The 12 h milled Fe–Si alloy powder showed the best electrochemical properties. Through the microstructural analysis of the Fe–Si alloy powders after the evaluation of half/full coin cells, powder resistance tests, and charge/discharge cycles, it was found that this was due to the low electrical conductivity and durability of β-FeSi2. The findings provide insight into the possible improvements in battery performance through the commercialization of Fe–Si alloy powders produced by over-milling in a mechanical alloying process.