The inherent high resistance of electrolyte/electrode interface in all-solid-state-lithium-secondary batteries (SSLB) poses a significant hurdle for the SSLB development. The interfacial resistivity between Li 7 La 3 Zr 2 O 12 (LLZ) and LiCoO 2 is decreased by introducing a thin Nb layer (~10 nm) at this interface. The interface modification approach using a Nb interlayer dramatically improves the discharge capacity and rate capability of a SSLB.

A comprehensive investigation has been performed of the static and dynamic behaviour of detached recombining plasmas in the linear divertor plasma simulator NAGDIS-II. For stationary plasma detachment, the transition from electron-ion recombination (EIR) to molecular activated recombination (MAR) has been observed by injecting hydrogen gas into high density helium plasmas. The particle loss rate due to MAR is found to be comparable to that of EIR. Experiments have also been performed by the injection of a plasma heat pulse produced by RF heating into the detached helium plasma to demonstrate the dynamic behaviour of volumetric plasma recombination. Negative spikes in the Balmer series line emission were observed and found to be similar to the so called negative ELM observed in tokamak divertors. Observed Balmer spectra were analysed in detail using the collisional-radiative model. A rapid increase of the ion flux to the target plate was observed associated with the re-ionization of the highly excited atoms generated by EIR.

The all-solid-state-lithium battery (SSLB) is a key technology to use Li metal anode with a theoretical capacity of 3860 mAhg −1 while suppressing the growth of Li dendrites. We present the model of Li nucleation on a solid-state electrolyte with metal current collector (CC)/lithium phosphorous oxynitride (LiPON) interfaces as the nucleation sites. We also observe the initial stage of Li growth and following Li dissolution using an in-situ scanning electron microscope (SEM) technique. The Li nucleation overpotential increases with increasing the Young's modulus of the CC. Also, the achievable Li particle sizes drastically increase with the Young's modulus of the CC. Our calculations show agreements with the experimental results and reveal that tensile stresses in a CC generate 10 −1 −10 0 GPa pressures on Li nuclei. Those pressures are three orders of magnitude larger than the ultimate tensile strength of bulk Li.The ten times larger theoretical capacity of Li metal anode (3860 mAhg −1 ) compared to graphite anode (372 mAhg −1 ) has attracted a great deal of interest. However, despite significant prior efforts, Li dendrite growth and a resulting rapid degradation in Coulombic efficiency (CE) have been unsolved critical problems. 1 On the other hand, solid-state electrolytes can be a solution to mechanically suppress Li dendrite growth toward the cathode without the help of separators. Hence, the all-solid-state-lithium battery (SSLB) provides innovative changes for not only increasing the overall battery energy density, but also developing "rechargeable" Li metal anodes.The Oak Ridge National Laboratory (ORNL) pioneered thin-film SSLBs using lithium phosphorus oxynitride (LiPON) electrolyte. 2,3 The first charging process nucleates Li metal on the anode side. ORNL demonstrated that the solid-state electrolyte completely blocked Li growth toward the cathode. Instead, Li grew to penetrate thick Cu current collectors (CC). Although thin-film SSLBs can operate over thousands of charge/discharge cycles under specific conditions as the ORNL has demonstrated, it is still obscure what mechanism dominates Li electrodeposition and dissolution on solid-state electrolytes.Nucleation sites are located at solid/solid interfaces in a SSLB. 4,5 Hence, the Li nuclei must deform either electrode or electrolyte to create their own spaces and keep growing. This process must be associated with the generation of strain energies at nucleation sites. The nucleation work on a heterogeneous substrate in a liquid electrolyte is usually divided into the surface work and the chemical work. 6 We also consider the mechanical work for Li nucleation and growth in a solid electrolyte system. We study the initial stage of Li electrodeposition using an in-situ scanning electron microscope (SEM) technique. Finally, we verify our model with CCs of different metals. ExperimentalThe top and bottom surfaces of a Li 1+x+y Al x Ti 2−x Si y P 3−y O 12 (LATP) sheet (1.25 cm × 1.25 cm, Ohara Co.) were coated with 2.5-μm-thick LiPON layers by radio frequency ...

No abstract

No abstract