Abstract: Disclosed is a piezoelectric energy harvesting apparatus. The piezoelectric energy harvesting apparatus includes: a piezoelectric energy harvesting array that includes a plurality of piezoelectric energy harvesting devices converting an external vibration into electric energy; a plurality of switches that is connected in series to the piezoelectric energy harvesting devices, respectively, and fits the resonance frequency of the piezoelectric energy harvesting array to the frequency of the external vibration by adjusting the resonance frequencies of the piezoelectric energy harvesting devices through the operation of the switches; and at least one or more rectifiers that convert alternating voltage outputted from the piezoelectric energy harvesting array into direct voltage.

Abstract: A method and apparatus for recognizing a user in an electronic device and automatically controlling an output value of the electronic device is provided. The method includes detecting user related data using at least one sensor, determining whether the user is a user who is previously registered in the electronic device using the detected user related data, and automatically adjusting at least one output value of the electronic device when the user is determined as the user who is previously registered in the electronic device, wherein at least the one sensor includes at least one of a camera sensor, a touch sensor, and a microphone sensor.

Abstract: Example embodiments herein relate to compositions useful in forming organic active patterns that may, in turn, be incorporated in organic memory devices. The compositions comprise N-containing conjugated electroconductive polymer(s), photoacid generator(s) and organic solvent(s) capable of dissolving suitable quantities of both the electroconductive polymer and the photoacid generator. Also disclosed are methods for patterning organic active layers formed using one or more of the compositions to produce organic active patterns, portions of which may be arranged between opposed electrodes to provide organic memory cells. The methods include directly exposing and developing the organic active layer to obtain fine patterns without the use of a separate masking pattern, for example, a photoresist pattern, thereby tending to simplify the fabrication process and reduce the associated costs.

Abstract: Disclosed herein is a volatile negative differential resistance device using metal nanoparticles, the device includes an organic layer disposed between two metal electrodes, in which the organic layer includes uniformly dispersed metal nanoparticles having a diameter of about 10 nm or less in an organic material. The device of this invention exhibits a volatile negative differential resistance phenomenon at room temperature upon application of a voltage and is thus suitable for use in various switching devices and logic devices, with excellent reproducibility and simple inexpensive processing.

Abstract: Provided are a method of manufacturing a lithium ion capacitor and a lithium ion capacitor manufactured using the same. The method of manufacturing a lithium ion capacitor includes forming a lithium thin film on one surface of a separator; making the lithium thin film in contact with an anode, and alternately disposing the anode and a cathode with the separator interposed therebetween to form an electrode cell; and enclosing the electrode cell and an electrolyte into a housing, and pre-doping lithium ions to the anode from the lithium thin film.

Abstract: A network system connected with one or more master devices and a method for operating the same. The system and method enable a new master device to be automatically connected to a network, when the network system is newly constructed or when the new master device is additionally connected to the network with which at least one master device has already been connected. A plurality of slave devices are connected to the network constructed within a building to transmit and receive data through the network. At least one master device controls the slave devices. A network manager automatically assigns a network address to the master device to appropriately connect the master device to the network when the master device is newly connected to the network or additionally connected to the network with which an existing master device is connected.

Abstract: Provided is an active piezoelectric energy harvester, which can control a direct current voltage applied to an embedded variable capacitance layer to precisely adjust a resonance frequency in real time, and thus achieve a simpler structure and a smaller size compared to a conventional one that adjusts the resonance frequency using a separate variable capacitor provided outside. Further, the active piezoelectric energy harvester can precisely adjust the resonance frequency even when the frequency of vibration varies over time as in a real natural vibration environment or when it is degraded to undergo a variation in its own resonance frequency, and thus can continuously maintain optimal energy conversion characteristics.

Abstract: Energy harvesting devices are provided. The energy harvesting device includes a body, a proof mass spaced apart from the body, a cantilever extending from the body onto the proof mass, a first electrode layer on the cantilever opposite to the body, a first piezoelectric layer on the first electrode layer, a second electrode layer on the first piezoelectric layer, a second piezoelectric layer on the second electrode layer, a pair of third electrode layers on the second piezoelectric layer, and a magnetic layer between the second electrode layer and the second piezoelectric layer. Related methods are also provided.

Abstract: There is provided an electric double layer capacitor package and a method of manufacturing the same. The electric double layer capacitor package includes an exterior case formed of insulating resin and having therein one or more partitions providing a plurality of housing spaces; a plurality of capacitor cells disposed in the plurality of housing spaces, respectively, each capacitor cell including first and second electrodes and a separator interposed between the first and second electrodes; and an internal series-connection terminal buried in each of the partitions and connecting the plurality of capacitor cells in series.

Abstract: An electrode active material having a partially crystalline structure in a fine area (short range), a method for preparing the same, and an electrochemical capacitor including the same. The electrode active material having a partially crystalline structure in a fine area (short range) can be prepared by performing heat treatment at a proper temperature. In a case where the electrode active material is used for an electrode of an electrochemical capacitor, the pores as well as the partially crystalline structure, of the electrode active material, can contribute to capacitance, and thus, energy density of the electrochemical capacitor can be significantly improved.

Abstract: A method for preparing electrode active material slurry including: mixing a conductive agent and a first thickener with a low molecular weight to primarily disperse the mixture; and mixing an active material and a second thickener with a higher molecular weight than the first thickener in the primary dispersion to secondarily disperse the mixture, and an electrochemical capacitor comprising an electrode using electrode active material slurry prepared by the method. It is possible to prepare a low resistance and high capacity electrochemical capacitor by selectively using at least two thickeners with different degrees of polymerization and molecular weights to remarkably improve dispersibility of an active material and a conductive agent. Particularly, it is possible to reduce resistance based on an electrochemical capacitor with the same capacity.

Abstract: Disclosed are an apparatus for harvesting/storing piezoelectric energy, including: a substrate having a groove at a side thereon; a piezoelectric MEMS cantilever having an end fixed to the substrate and the other end floating above the groove, and configured to convert and store an external vibration into electric energy; and a mass formed at one end of the piezoelectric MEMS cantilever and configured to apply a vibration, and a manufacturing method thereof.

Abstract: Provided is an energy harvesting electric device capable of increasing output power. The energy harvesting electric device includes an energy harvester array including a plurality of energy harvesters, a single rectifier connected to the energy harvester array, and an output unit which is connected to the single rectifier and has a load resistance. The energy harvesters include a plurality of first energy harvesters connected to each other in parallel and a single second energy harvester connected in parallel to the first energy harvesters. The first energy harvesters have a first specific resistance higher than the load resistance and the second energy harvester has a second specific resistance higher than the first specific resistance.

Abstract: An electric double layer capacitor (EDLC) includes an electric double layer cell and first and second external electrodes. The electric double layer cell includes a separator and at least one first polarizable electrode and at least one second polarizable electrode. The first and second external electrodes are formed at first and second side surfaces of the electric double layer cell facing each other, respectively. The first polarizable electrode includes a first current collection layer and a first active material layer formed on either surface of the first current collection layer facing the separator and the second polarizable electrode includes a second current collection layer and a second active material layer formed on either surface of the second current collection layer facing the separator.

Abstract: There are provided an electrolyte for a lithium ion capacitor and a lithium ion capacitor including the same. The electrolyte for a lithium ion capacitor according to the present invention includes: a lithium salt; and a mixing solvent including i) two or more compounds selected from a group consisting of cyclic carbonate compounds, ii) one or more compounds selected from a group consisting of linear carbonate compounds represented by a specified Formula, and iii) one or more compound selected from a group consisting of propionate compound represented by a specified Formula.

Abstract: Provided are a piezoelectric energy harvester and a method of manufacturing the same. The piezoelectric energy harvester is configured to obtain primary voltage from a piezoelectric layer vibrated to generate voltage and secondary voltage from a magnetostrictive layer vibrated to induce a change in magnetic field and a coil surrounding the magnetostrictive layer. Thus, it is possible to obtain sufficient voltage to drive a power conditioning circuit (PCC).

Abstract: A cathode active material, a method for preparing the same, and a lithium ion capacitor including the same. The cathode active material has a surface with a porous structure and an inside with an amorphous structure where crystalline phases are not present. The cathode active material according to the present invention has the inside having an amorphous structure where crystal lattices are not contained in a short range order, thereby preventing the lithium ions from being intercalated into the inside of the cathode active material while the anode is pre-doped. The lithium ion capacitor containing the cathode active material having the above structure can maintain a potential difference between the cathode and the anode constantly, thereby obtaining high withstand voltage, high energy density, and high input and output characteristics. Furthermore, a large-capacitance lithium ion capacitor device having excellent reliability of high-speed charging and discharging cycle can be manufactured.

Abstract: A method of manufacturing a chip-type electric double layer capacitor, including: forming a lower case having an opened housing space and first and second external terminals buried therein, the first and second external terminals having first surfaces exposed to the housing space, respectively, and second surfaces exposed to an outer region of the lower case, respectively; mounting an electric double layer capacitor cell in the housing space such that the electric double layer capacitor cell is electrically connected to the first surfaces of the first and second external terminals exposed to the housing space; and mounting an upper cap on the lower case so as to cover the housing space.

Abstract: Disclosed herein are a method for pre-doping an anode and a lithium ion capacitor storage device including the same. The method of the present invention includes: disposing lithium metal films and anodes alternately; and charging the lithium metal films and the anodes to directly pre-dope lithium metal contained in the lithium metal films onto the anodes. The lithium ion capacitor storage device is manufactured by the method. According to the present invention, the lithium ion capacitor storage device including the anode can provide a high-capacitance capacitor capable of operating even at a high voltage range of up to 3.8V to 2.0V, and ensure high reliability even in a high-temperature (60° C.) cycle.

Abstract: Disclosed herein are an electrolyte solution composition and an energy storage device including the same. The electrolyte solution may include: a solvent including one or more compound selected from one or more cyclic carbonate compound; and additives including one or more selected from a group consisting of catechol carbonate (CC), fluoro ethylene carbonate (FEC), propane sulton (PS), and propene sulton (PST).