Naoaki Yabuuchi 교수

ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTResearch Development on Sodium-Ion BatteriesNaoaki Yabuuchi†‡, Kei Kubota†‡, Mouad Dahbi†‡, and Shinichi Komaba*†‡View Author Information† Department of Applied Chemistry, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8061, Japan‡ Elements Strategy Initiative for Catalysts and Batteries (ESICB), Kyoto University, Katsura, Kyoto 615-8520, Japan*E-mail: [email protected]Cite this: Chem. Rev. 2014, 114, 23, 11636–11682Publication Date (W

Lithium-excess manganese layered oxides, which are commonly described by the chemical formula zLi(2)MnO(3)-(1-z)LiMeO(2) (Me = Co, Ni, Mn, etc.), are of great importance as positive electrode materials for rechargeable lithium batteries. In this Article, Li(x)Co(0.13)Ni(0.13)Mn(0.54)O(2-δ) samples are prepared from Li(1.2)Ni(0.13)Co(0.13)Mn(0.54)O(2) (or 0.5Li(2)MnO(3)-0.5LiCo(1/3)Ni(1/3)Mn(1/3)O(2)) by an electrochemical oxidation/reduction process in an electrochemical cell to study a reaction

Rechargeable lithium batteries have rapidly risen to prominence as fundamental devices for green and sustainable energy development. Lithium batteries are now used as power sources for electric vehicles. However, materials innovations are still needed to satisfy the growing demand for increasing energy density of lithium batteries. In the past decade, lithium-excess compounds, Li2MeO3 (Me = Mn(4+), Ru(4+), etc.), have been extensively studied as high-capacity positive electrode materials. Althou

Further increase in energy density of lithium batteries is needed for zero emission vehicles. However, energy density is restricted by unavoidable theoretical limits for positive electrodes used in commercial applications. One possibility towards energy densities exceeding these limits is to utilize anion (oxide ion) redox, instead of classical transition metal redox. Nevertheless, origin of activation of the oxide ion and its stabilization mechanism are not fully understood. Here we demonstrate

A new and promising P2‐type layered oxide, Na 5/6 [Li 1/4 Mn 3/4 ]O 2 is prepared using a solid‐state method. Detailed crystal structures of the sample are analyzed by synchrotron X‐ray diffraction combined with high‐resolution neutron diffraction. P2‐type Na 5/6 [Li 1/4 Mn 3/4 ]O 2 consists of two MeO 2 layers with partial in‐plane √3 a × √3 a ‐type Li/Mn ordering. Na/Li ion‐exchange in a molten salt results in a phase transition accompanied with glide of [Li 1/4 Mn 3/4 ]O 2 layers without the

Single phase, well-crystallized O3-type NaFeO2 (alpha NaFeO2) is prepared by a solid-state method. Electrode performance of O3-type NaFeO2 is examined as positive electrode materials for rechargeable sodium batteries. O3-type NaFeO2 can deliver 80–100 mAh g−1 of reversible capacity with a nearly flat voltage profile at approximately 3.3 V vs. Na metal. The electrode performance is significantly deteriorated by oxidation beyond x > 0.5 in Na1−xFeO2. X-ray diffraction study reveals that loss of el

Reaction mechanism of was examined by ex situ X-ray diffraction (XRD) and electrochemical methods. According to XRD results, the change in hexagonal lattice parameters was quite similar to that of , i.e., the unit cell volume was almost constant at in , indicating homogeneous phase reaction over an entire range. Reversible-potential measurements on against a lithium electrode were also carried out and the solid-state redox reactions were described by applying the concept of electrochemical densi

A new high-capacity electrode material made from only earth-abundant elements.

Large-scale high-energy batteries with electrode materials made from the Earth-abundant elements are needed to achieve sustainable energy development. On the basis of material abundance, rechargeable sodium batteries with iron- and manganese-based positive electrode materials are the ideal candidates for large-scale batteries. In this review, iron- and manganese-based electrode materials, oxides, phosphates, fluorides, etc, as positive electrodes for rechargeable sodium batteries are reviewed. I

Abstract The electrode performance of amorphous phosphorus in aprotic Na cells is examined. Amorphous phosphorus is electrochemically reduced in the Na cells with a three‐electron redox process, crystallizing into Na 3 P. NaP bonds in Na 3 P have high covalent characteristics. Therefore, the molar volume of Na in Na 3 P is anomalously small in comparison to other Na–metal alloys that have been used as negative electrode materials. The theoretical volumetric capacity, calculated at full volume e

NaFex(Ni1/2Mn1/2)1-xO2 layered oxides are synthesized by a solid-state method, and their electrode properties as positive electrodes for rechargeable sodium batteries are examined. Crystallographic analysis on a series of samples reveals that NaFex(Ni1/2Mn1/2)1-xO2 samples crystallize into a solid solution between two end-members of O3-type Na(Ni1/2Mn1/2)O2 and NaFeO2. A Na/NaFe0.4(Ni1/2Mn1/2)0.6O2 cell delivers 130 mAh g−1 of reversible capacity in a voltage range of 2.0 – 3.8 V. Energy density

was prepared and characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), electron diffraction (ED), X-ray diffraction (XRD), and X-ray absorption fine structure (XAFS) to examine whether or not our first-principles calculation properly predicted a new lithium insertion material of . High-resolution TEM image directly showed the layered structure having a cubic close-packed oxygen array. The [00.1]-zone electron diffraction pattern showed a -

Graphite/silicon composite electrodes are prepared with PANa polymer as a binder. Morphological characters and electrode performance are compared with those of PVdF. The PANa layer behaves like SEI at the interface with ionic liquid, resulting in the highly reversible electrode performance. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the auth