Recent development of sulfide solid electrolytes and interfacial modification for all-solid-state rechargeable lithium batteries

AbstractRecent development of inorganic sulfide solid electrolytes and all-solid-state rechargeable lithium batteries with them is reviewed. Electrical conductivity, electrochemical stability and chemical stability of these sulfide electrolytes are reported. Formation of favorable solid–solid contacts between electrode and electrolyte is important in all-solid-state batteries. Useful techniques to achieving intimate electrode–electrolyte interfaces are proposed. Application of sulfur positive electrode and lithium metal negative electrode with large theoretical capacity to all-solid-state lithium batteries is demonstrated

Kinetics of Interfacial Lithium-ion Transfer between a Graphite Negative Electrode and a Li₂S-P₂S₅ Glassy Solid Electrolyte

All-solid-state lithium-ion batteries that use sulfide solid electrolytes have attracted much attention due to their high safety and wide electrochemical window. In this study, highly oriented pyrolytic graphite (HOPG) and 75Li₂S-25P₂S₅ (mol%) glass were used as a model graphite negative electrode and a sulfide solid electrolyte, respectively. Interfacial lithium-ion transfer between 75Li₂S-25P₂S₅ glass and the HOPG electrode was studied by AC impedance spectroscopy measurements. The activation energy of the interfacial lithium-ion transfer was estimated to be around 37 kJ mol⁻¹, which was much smaller than that at the interface between organic liquid electrolytes and HOPG electrode, indicating that the lithium-ion transfer at the interface between 75Li₂S-25P₂S₅ glass and HOPG electrode proceeded quite rapidly. Furthermore, surface deposition of TiO₂ and surface oxidation on HOPG electrodes were performed using the atomic layer deposition (ALD) method. Interfacial lithium-ion transfer between 75Li₂S-25P₂S₅ glass and ALD-modified-HOPG electrodes was also investigated. The activation energies of the interfacial lithium-ion transfer were slightly higher than that of HOPG, but the resistance of the charge-transfer process was lower, indicating that the affinity of the HOPG electrode for the glass electrolyte was improved by surface modification

Unique Li deposition behavior in Li₃PS₄ solid electrolyte observed via operando X-ray computed tomography

The problem of lithium dendrites must be addressed for practical lithium metal all-solid-state batteries. Herein, three-dimensional morphological changes within Li₃PS₄ electrolyte away from the anode were observed using operando X-ray computed tomography. We revealed that the electronic conduction of decomposition and the electrolyte/void interface cause the lithium deposition within the Li₃PS₄

A reversible oxygen redox reaction in bulk-type all-solid-state batteries

An all-solid-state lithium battery using inorganic solid electrolytes requires safety assurance and improved energy density, both of which are issues in large-scale applications of lithium-ion batteries. Utilization of high-capacity lithium-excess electrode materials is effective for the further increase in energy density. However, they have never been applied to all-solid-state batteries. Operational difficulty of all-solid-state batteries using them generally lies in the construction of the electrode-electrolyte interface. By the amorphization of Li₂RuO₃ as a lithium-excess model material with Li₂SO₄, here, we have first demonstrated a reversible oxygen redox reaction in all-solid-state batteries. Amorphous nature of the Li₂RuO₃-Li₂SO₄ matrix enables inclusion of active material with high conductivity and ductility for achieving favorable interfaces with charge transfer capabilities, leading to the stable operation of all-solid-state batteries

Severe esophagitis directly induced by accumulation of crizotinib-residue at the esophageal mucosa proven with polarizing microscope examination

Crizotinib demonstrates dramatic effects for the patients with echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase gene (ALK) fusion or c-ros oncogene 1 (ROS-1) fusion-positive lung cancer, with some characteristic toxicities. Although several studies reported that serious esophagitis was induced by crizotinib, the detailed mechanisms and ways to ameliorate the esophagitis have not been clarified. In this report, we report two cases with lung cancer who had been treated with crizotinib and developed severe esophagitis. Polarizing microscope examination clearly revealed that the accumulation of crizotinib-residue in the esophageal biopsy samples at the second anatomical narrowing of the esophagus in both cases. Since it seemed that the accumulation of crizotinib-residue in the esophageal mucosa directly caused the esophageal inflammation, we recommended taking crizotinib with a large amount of water (more than 200 ml) and to stay sitting upright for 30 minutes after intake. After that, the esophagitis gradually improved and the patients could continue taking crizotinib without dose reduction or withdrawal. Our experiences suggest that this crizotinib-induced esophagitis could be easily prevented by proper administration of crizotinib

8 kbit/s オンセイ フゴウカ ITU-T ヒョウジュン ノ エンザンリョウ サクゲンバン Annex A カンコク ノ ケイイ ト ヒンシツ ヒョウカ ジョウホウ ヒョウゲン ガッカ

ITU-Tの8 kbit/s音声符号化方式G.729の演算量削減版がAnnex Aとして勧告された経緯とのアルゴリズムの特徴、及び、品質評価について述べる。Annex Aは、電話網上でモデムを介して、PC等の端末装置間でディジタルデータと音声とを同時に送受する方式DSVD (Digital Simultaneous Voice and Data)のITU-T勧告V.70に使われることを主目的として、G.729の演算量削減により開発された。DSVD用音声符号化式は、低ビットレート、商用電話品質、短遅延時間、低演算量が望まれ、また、伝送効率の要請からVAD(voice Activity Detection)機能の併用が必須である。G.729 CS-ACELPは、演算量を除いてほぼすべて要求を満たしていたが、Annex Aは演算量を大幅に削減し、DSVDの要求に合致させたものである。品質評価は、日本語ほか複数国語で行われ、G.729本体とAnnex Aが相互に接続可能であり、かつ、所定の品質条件を満たすことが明らかとなった。DSVD方式はその後、インターネット上のバケット音声通信にとって代わられるが、音声符号化標準は広くVoIP(Voice over Internet Protocol)などに使用されその用途が拡大している。This paper presents the history of recommending Annex A to G.729 in ITU-T (international Telecommunication Union, Telecommunication Standerdization Sector) and quality assessment of the coder. The requirements for this system were toll speech quality, low complexity, and short delay time at low bit-rate less than 12 kbit/s, and were not met by existing speech coding standards. Rreduced complexity CS-ACELP was selected from among 5 candidates as the coding algorithm after extensive subjective selection tests and was recommended as Annex A to G.729. The subjective test in Japanese shows that this Annex is compatible with G.729 and meets all the requirements