859results about How to "Improve life characteristics" patented technology

A nitride semiconductor laser device has a group III nitride semiconductor multilayer structure. The group III nitride semiconductor multilayer structure includes an n-type semiconductor layer, a p-type semiconductor layer and a light emitting layer held between the n-type semiconductor layer and the p-type semiconductor layer, and the p-type semiconductor layer is formed by successively stacking a p-side guide layer, a p-type electron blocking layer in contact with the p-side guide layer and a p-type cladding layer in contact with the p-type electron blocking layer from the side closer to the light emitting layer. The p-side guide layer is formed by stacking a layer made of a group III nitride semiconductor containing Al and a layer made of a group III nitride semiconductor containing no Al. The p-type cladding layer is made of a group III nitride semiconductor containing Al, and the p-type electron blocking layer is made of a group III nitride semiconductor having a larger Al composition than the p-type cladding layer.

An electrolyte for a lithium secondary battery, the electrolyte including: a lithium salt; a non-aqueous organic solvent; and a piperazine derivative represented by Formula 1 having an oxidation potential lower than an oxidation potential of the non-aqueous organic solvent by about 2 V to about 4 V:

wherein, in Formula 1, X, Y, and R₁ to R₄ are defined in the specification.

In a stacked display device with light-emitting units composed of organic layers and stacked together, the use of a stable material in at least a portion of a charge generation layer makes it possible to achieve improvements in environmental stability and also to attain an improvement in the efficiency of injection of charges from the charge generation layer into the light-emitting units. The display device can be readily fabricated. In a display device (11) provided with a plurality of light-emitting units (14-1)(14-2), each of which includes at least an organic light-emitting layer (14c), stacked together between a cathode (16) and an anode (13), and also with a charge generation layer (15) held between the respective light-emitting units (14-1)(14-2), at least a portion of the charge generation layer (15) is composed of an oxide or fluoride which contains at least one of alkali metals and alkaline earth metals.

The invention relates to an electroluminescent compound and an electroluminescent device comprising the same. The electroluminescent compound is characterized in that the electroluminescent compound is indicated by the following chemical formula (1) and has a non-symmetric structure with L---L' as a benchmark. According to the electroluminescent compound, substituent groups having high efficiency or long service life are respectively combined with pryene compound in a non-symmetric way, so illuminating efficiency and service life are improved and excitation purity and thermal stability are enhanced; the electroluminescent device comprising the same also has excellent excitation purity, illuminating efficiency and long service life; and the electroluminescent compound can be applied to various displaying elements.

Provided are a positive active material that has a decreased amount of Li-containing impurities that remain on a lithium transition metal composite oxide surface to decrease an amount of gas generation and has improved lifespan properties, a method of preparing the same, a positive electrode for a lithium secondary battery including the positive active material, and a lithium secondary battery including the same.

Provided are a nickel-based active material, a method of preparing the same, and a lithium secondary battery including a positive electrode including the nickel-based active material. The nickel-based active material includes at least one secondary particle including an aggregate of two or more primary particles, wherein at least a portion of the secondary particle has a radial array structure, and a hetero-element compound is positioned between the primary particles.

A multilayer ceramic capacitor has a laminate comprising dielectric layers stacked alternately with internal electrode layers of different polarities, wherein: the dielectric layers contain ceramic grains whose primary component is BaTiO₃; the ceramic grains contain at least one type of donor element (D) selected from the group that includes Nb, Mo, Ta, and W, and at least one type of acceptor element (A) selected from the group that includes Mg and Mn; and the ratio of the concentration of the donor element (D) and that of the acceptor element (A) (D/A) is greater than 1 at the center parts of the ceramic grains, while the D/A ratio is less than 1 at the outer edge parts of the ceramic grains (if A=0, then D/A=∞ and D=A=0 never occurs).

The present invention relates to an anode for a lithium secondary battery, comprising: an electrode collector; and a multilayer structure including a primary anode active material layer including a first anode active material formed on the electrode collector, and a secondary anode active material layer including a second anode active material formed on the first anode active material layer and having a relatively low density and a relatively large average particle size. The anode according to one embodiment of the present invention can improve a charging characteristic and a lifespan characteristic of the lithium secondary battery by improving the porosity of the surface of an electrode after a rolling process by including a multilayer active material layer including two kinds of anode active materials having different rolling densities and average particle sizes on the electrode collector, so as to improve mobility of ions into the inside of the electrode.

Disclosed is a light-emitting diode drive device that improves the utilization efficiency and power factor of LEDs while maintaining power supply efficiency. Said light-emitting diode drive device is provided with: a rectification circuit (2) that can be connected to an AC power supply and rectifies the AC voltage from said AC power supply into a pulsed voltage; a first LED block (11) comprising a plurality of light-emitting diodes, a second LED block (12) comprising a plurality of light-emitting diodes, and a third LED block (13) comprising a plurality of light-emitting diodes, connected sequentially in series to the output side of the rectification circuit (2); a first switching means that turns a first bypass path (BP1), which bypasses the second LED block (12), on or off on the basis of the amount of power supplied to the first LED block (11); and a second switching means that turns a second bypass path (BP2), which bypasses the third LED block (13), on or off on the basis of the amount of power supplied to the first LED block (11) and the second LED block (12).

The invention relates to a lithium-transition metal compound powder for a positive-electrode material for lithium secondary battery which comprises secondary particles configured of primary particles having two or more compositions and a lithium-transition metal compound having a function of being capable of insertion and release of lithium ions, wherein the powder gives a pore distribution curve having a peak at a pore radium 80 nm or greater but less than 800 nm, and the secondary particles include primary particles of a compound represented by a structural formula including at least one element selected from As, Ge, P, Pb, Sb, Si and Sn, wherein the primary particles of the compound are present at least in an inner part of the secondary particles.

Disclosed is an electrolyte comprising a compound having both a sulfonate group and a cyclic carbonate group. The electrolyte forms a more stable and dense SEI layer on the surface of an anode, and thus improves the capacity maintenance characteristics and lifespan characteristics of a battery. Also, disclosed is a compound represented by the following Formula 1, and a method for preparing the same by reacting 4-(hydroxyalkyl)-1,3-dioxolan-2-one with a sulfonyl halide compound:

A nitride semiconductor laser device comprises a nitride semiconductor substrate (101); a nitride semiconductor lamination structure that has an n-type semiconductor layer (102), an active layer (104) and a p-type semiconductor layer (103) laminated on or above the nitride semiconductor substrate (101), and has a stripe-shaped waveguide region for laser light; and end surface protective films (110) on the both end surfaces substantially perpendicular to the waveguide region. In the nitride semiconductor laser device, the nitride semiconductor substrate (101) has a luminescent radiation region (112) that absorbs light emitted from the active layer (104) and emits luminescent radiation with a wavelength longer than the wavelength of the emitted light, and the end surface protective films (110) have a high reflectivity for the wavelength of the luminescent radiation from the luminescent radiation region (112). Accordingly, a nitride semiconductor laser device that does not improperly operate and has excellent FFP is provided.

An additive for an electrolyte solution includes a lithium salt having an oxalato complex as an anion and a compound represented by following Chemical Formula 1.

Wherein, a represents C or Si, b represents H or F, and n represents an integer of 1 to 5. A non-aqueous electrolyte solution including the additive and a lithium secondary battery including the electrolyte solution also are provided.

The present invention provides a positive electrode active material for a secondary battery and a secondary battery including the same, which includes a core; a shell located to surround the core; and a buffer layer located between the core and the shell, and including a three-dimensional network structure connecting the core and the shell and a pore, in which the core, the shell, and the three-dimensional network structure in the buffer layer each independently include a lithium nickel-manganese-cobalt-based composite metal oxide, and the positive electrode active material has a BET specific surface area of 0.2 m²/g to 0.5 m²/g, a porosity of 30 vol % or less, and an average particle size (D₅₀) of 8 μm to 15 μm. The decomposition of the active material may be minimized by a rolling process in the manufacture of an electrode by controlling the specific surface area, average particle diameter and porosity of the active material particles as well as the specific structure, the reactivity with an electrolyte solution may be maximized, and the output and lifespan characteristics of the secondary battery may be improved since the particles forming the shell have crystal structure with orientation which facilitates intercalation and deintercalation of lithium ions.

A solid-state battery including a cathode, an anode, and a solid-state electrolyte layer including a solid-state electrolyte, wherein the solid-state electrolyte layer is disposed between the cathode and the anode, wherein the anode includes an anode active material, a first binder, and a second binder, the first binder is inactive to the solid-state electrolyte, the second binder has a tensile modulus greater than a tensile modulus of the first binder, and the second binder has a binding force which is greater than a binding force of the first binder.

An anode, a lithium battery including the anode, and a method of preparing the anode. The anode includes a current collector; a first anode layer disposed on the current collector; a second anode layer disposed on the first anode layer; and an inorganic protection layer disposed on the second anode layer, wherein an oxidation/reduction potential of the first anode layer and an oxidation/reduction potential of the second anode layer are different from each other.

A nitride semiconductor laser diode includes a substrate, an n-side nitride semiconductor layer formed on the substrate, an active layer formed on the n-side nitride semiconductor layer and having a light emitting layer including In_xAl_yGa_1−x−yN (0<x<1, 0 y<1, 0<x+y<1), and a p-side nitride semiconductor layer formed on the active layer. In the nitride semiconductor laser diode, the lasing wavelength of the nitride semiconductor laser diode is 500 nm or greater, dislocations originated in the active layer penetrate through the p-side nitride semiconductor layer, with the dislocation density in the p-side nitride semiconductor layer being 1×10⁶ cm⁻² or greater, and the concentration distribution of p-type impuritys in the depth direction is such that, from the light emitting layer toward the surface of the p-side nitride semiconductor layer, the concentration of the p-type impurity reaches a maximum value of 5×10¹⁸ cm⁻³ or greater within a range of 300 nm from the top portion of the light emitting layer which is closest to the p-side nitride semiconductor layer, and after reaching the maximum value, the concentration remains at 6×10¹⁷ cm⁻³ or greater in the above-described range of 300 nm.

Provided are a compound for an organic optoelectronic device represented by Chemical Formula 1, an organic light emitting diode including the same, and a display device including the organic light emitting diode. The structure of Chemical Formula 1 is shown in the specification.

The compound for an organic optoelectronic device provides an organic light emitting diode having life-span characteristics due to excellent electrochemical and thermal stability, and having high luminous efficiency at a low driving voltage.

A binder composition for a rechargeable battery, including a binder polymer having a glass transition temperature (Tg) of 20° C. or less, and having a storage modulus (60° C.) of 50-150 MPa. The binder composition according to an embodiment can improve life characteristics of the rechargeable battery by efficiently controlling expansion of a negative electrode plate.

A dielectric ceramic that includes a sintered body of BaTiO₃ based ceramic grains, in which the ceramic grains each include a shell part as a surface layer part and a core part inside the shell part. The ceramic grains contain, as accessory constituents, R (R, which is a rare-earth element, is at least one selected from the group consisting of Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, and Y) and M (M is at least one selected from the group consisting of Mg, Mn, Ni, Co, Fe, Cr, Cu, Al, Mo, W, and V). R and M are present in the shell part of the ceramic grain, and concentrations of R and M contained in the shell part are increased from a grain boundary toward the core part.