Nagoya University · 공학
타카유키 야마다 교수의 연구실은 주로 고체 이온 도전성 물질, 특히 리튬 기반 고체 전해질과 그 응용에 중점을 두고 있습니다. 리튬 리치 옥시할라이드 및 반퍼스킷 구조를 가진 고체 전해질의 합성, 상전이, 이온 전도도 향상 메커니즘을 체계적으로 연구하며, 전기화학적 안정성과 전기적 성능 간의 상관관계를 규명하고자 합니다. 특히, 리튬 이온 이동성 향상을 위한 화학 조절, 나노구조 제어, 고체형 리튬 이on 배터리의 실용화를 위한 박막 구조 설계에 뛰어난 기여를 하고 있습니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
The authors have investigated the chemical states at the interface of metal/perovskite oxides both with and without bipolar resistive switching (RS) behavior using photoemission spectroscopy and x-ray absorption spectroscopy. Al/Pr0.7Ca0.3MnO3 (PCMO), Al/La0.7Ca0.3MnO3 (LCMO), and Al/La0.33Sr0.67FeO3 interfaces were chosen as typical examples of interfaces for the perovskite-based resistance random access memory (ReRAM), while Pt/PCMO and Ag/LCMO were chosen as references for the metal/perovskit
Lithium-rich antiperovskites (Li3–xOHxX (X = Cl, Br)) are considered as promising electrolyte candidates for all-solid-state lithium secondary batteries with Li metal as the negative electrode owing to their soft nature and similarity to sulfide-based solid electrolytes. However, it has been reported that all-solid-state batteries with Li3–xOHxX exhibit low cycling stability. Although the reasons for this are not fully understood, one possibility could be the electrochemical instability of Li3–x
Lithium metal is a potential anode material to develop all-solid-state battery (SSB) with high energy density. However, Li metal easily reacts with atmospheric component (H2O, CO2, O2, N2) and then Li metal must be treated sensitively for industrial applications. Here, we report an inverted-stack Li-free thin-film SSB, SUS/Pt/LiPON/LiCoO2/Au, where highly-crystalline LiCoO2 thin film is formed on amorphous LiPON thin film at room temperature by aerosol deposition and Li metal is electrochemicall
The oxyhalide-based solid electrolyte Li<sub>2</sub>OHCl usually forms the thermodynamically stable orthorhombic phase at room temperature and shows poor lithium ionic conductivity. Above 35 °C, a structural phase transition into the cubic phase occurs and ionic conductivity is enhanced. In this work, mechanochemical synthesis of Li<sub>2</sub>OHCl is reported. The as-prepared Li<sub>2</sub>OHCl formed a cubic <i>Pm</i>3̅<i>m</i> structure and showed an ionic conductivity of 2.6 × 10<sup>-6</sup
We report that mixed-halogen anti-perovskite-type Li2OHBr1−xXx (X = Cl, I and x = 0–1) materials are prepared by room temperature ball-milling process, and investigate how the halogen mixing affects the total Li+ conductivity. Both solid solution ranges and lattice constants depend on the species of X. Among them, though X = I compounds form solid solution in narrow range of x smaller than 0.15, Li2OHBr0.9I0.1 shows the largest lattice constant and the highest total ionic conductivity at 25 °C (
This paper describes about the effect of Li-H exchange amount on total lithium-ion (Li<sup>+</sup>) conductivity of Li<sub>2+<i>x</i></sub>OH<sub>1-<i>x</i></sub>Br (<i>x</i> = -0.5 to +0.4). These samples are systematically prepared at room temperature by a dry ball-milling process using LiOH, LiOH·H<sub>2</sub>O, Li<sub>2</sub>O, and LiBr as starting materials. Synchrotron X-ray diffraction analysis reveals that single-phase Li<sub>2+<i>x</i></sub>OH<sub>1-<i>x</i></sub>Br samples are formed w
Oxide-based all-solid-state batteries (OX-SSBs) have been expected as next generation rechargeable batteries. In the OX-SSBs, charge transfer reaction occurs at electrode-solid electrolyte interface and then both of them must adhere well with smaller interfacial ion transfer resistance. Although various kinds of electrodes and solid electrolytes have been proposed, most of them are composed of different elements and concentrations, and, in addition, they have different thermal stability. Thus, s
Abstract Effects of target-substrate (TS) distance during pulsed laser deposition process on the chemical structure and lithium-ion conductivity of amorphous lithium phosphate (LPO) thin films are investigated. The shorter TS distance results in lower Li concentration, longer phosphate chain, and higher ionic conductivity. The ionic conductivity of 2.7 × 10−7 S/cm is obtained at 25 °C in the LPO thin film with short TS distance.
A method of simulating the transient response of semiconductor diodes with deep impurity levels has been established. This has enabled us to visualize the space charge overlapping model of switching when carriers are sufficiently injected and carrier-capture time is shorter than transit time. The results confirmed this model. Delay time in this case is dominated by the carrier transit time through the diode. In the case of shorter transit time, the rate of carrier supply by injection is the domi
