Nec Corporation

Azbil Corporation

Nec Energy Devices, Ltd.

Yamatake Corporation

Tetsuya Kajita

Tatsuji Numata

Jiro Iriyama

Daisuke Kawasaki

Ryuichi Kasahara

Hiroo Takahashi

Shin Serizawa

Kouji Okuda

Kazuhiko Inoue

Yutaka Harada

Ichiro Mitsutake

Naoki Nagashima

Yasutaka Kono

Hiroshi Hatanaka

Emiko Fujii

Taka Inoue

Seita Nashimoto

Taichiro Kato

Taichirou Kato

A digital filter includes: integration calculation units () that are cascade-connected, are fed time-division-multiplexed data, the time-division-multiplexed data being formed of pieces of data on M channels that are time-division multiplexed, the pieces of data on the respective channels being updated at a rate equal to a sampling frequency f, operate in accordance with a clock having a frequency f&#xd7;M, and integrate the time-division-multiplexed data for every M samples; a frequency conversion unit () that operates in accordance with a clock having a frequency f&#xd7;M, decimates data at the sampling frequency finput from the integration calculation unit () in the last stage at a sampling frequency f, and delays data obtained as a result of decimation by (M&#x2212;1) samples; and difference calculation units () that operate in accordance with the clock having the frequency f&#xd7;M, are cascade-connected to the output of the frequency conversion unit (), and each subtract, from data input thereto, data M samples before.

Digital filter

The present invention relates to an electrode binder composition including a high-molecular-weight poly(amic acid) having a weight-average molecular weight of 5,000 or more and 100,000 or less and a low-molecular-weight poly(amic acid) having a weight-average molecular weight of 100 or more and 2,000 or less, and the present invention can provide an electrode binder composition that leads to a secondary battery having a high capacity superior in the initial charge/discharge efficiency and the cycle characteristics.

Electrode binder composition and electrode

An output circuit () according to the present invention includes a first output terminal (VO) and a second output terminal (SGND); an output transistor (MP) connected between a first fixed-potential node (VCC) and the first output terminal; an output load () connected between the first output terminal and the second output terminal; a control circuit () that controls the output transistor so that a monitor voltage (VS) based on a voltage between the first output terminal and the second output terminal matches an input voltage (VI); a constant voltage source () whose one end is connected to the second terminal and whose other end is connected to a second fixed-potential node (GND); and a circuit (R) that forms a current path between the first output terminal and the second fixed-potential node. Accordingly, in the output circuit, stability of a negative feedback loop can be enhanced, and linearity of an output voltage with respect to an input voltage can be enhanced.

Output circuit and voltage generating device

A digital filter includes integrator circuits configured to operate based on a clock of a sampling frequency fthat is equal to a sampling frequency of input data and determine a sum of the input data on a sample-by-sample basis, a frequency converter circuit configured to perform decimation on data of the sampling frequency fto reduce the sampling frequency fto a sampling frequency f=f/N, one or more differentiator circuits configured to operate based on a clock of the sampling frequency fand subtract data of an immediately preceding sample from the input data, a differentiator circuit for removal of 50 Hz configured to operate based on the clock of the sampling frequency fand subtract, from the input data, data preceding the input data by a plurality of samples, and a differentiator circuit for removal of 60 Hz configured to operate based on a clock of the sampling frequency fand subtract, from the input data, data preceding the input data by a plurality of samples.

Disclosed is a startup circuit comprises a current path comprising a circuit including a P-channel MOS transistor, a P-channel MOS transistor, and an N-channel MOS transistor connected in series. After a constant current circuit is started, the N-channel MOS transistor is turned on, an operating current is fed through the current path, and an N-channel MOS transistor is turned off to cut off a startup current. After the startup current is cut off, the gate voltage of the P-channel MOS transistor is controlled by the voltage (bias voltage during operation of the constant current circuit) of a node, a drain-source voltage of the P-channel MOS transistor is reduced, and the operating current flowing through the current path is limited.

Startup circuit

A control system for a lithium secondary battery measures a voltage V of a negative electrode that uses silicon oxide as a negative electrode active material, with respect to a lithium reference electrode and a discharge capacity Q of the lithium secondary battery during discharge of the lithium secondary battery; generates a V&#x2212;dQ/dV curve representing a relationship between dQ/dV, which is a proportion of an amount of change dQ in the discharge capacity Q to an amount of change dV in the voltage V, and the voltage V; calculates an intensity ratio of two peaks appearing on the V&#x2212;dQ/dV curve for two voltage values in the voltage V; and senses a state of the negative electrode utilizing the intensity ratio.

System and method for detecting a state of a lithium secondary battery by measuring a voltage of a negative electrode with respect to a reference electrode

Provided is a negative electrode active material for a lithium secondary cell, the material having the function of a binder for the active material, and being capable of stable reversible reactions with lithium. Also, provided are an extended-life lithium secondary cell having improved energy density and stable charge/discharge, and a method for producing the same. The negative electrode active material for a lithium secondary cell is polyimide represented by formula (1) (wherein R1 and R2 independently denote an alkyl, alkoxy, acyl, phenyl, or phenoxy group).

Negative electrode active material for lithium secondary cell, lithium secondary cell employing the same, and method for producing the same

Provided is a nonaqueous electrolytic solution secondary battery having a high energy density, and a positive electrode and a negative electrode used therefor. The nonaqueous electrolytic solution secondary battery includes a positive electrode and a negative electrode, wherein: the negative electrode contains a negative electrode active material having an initial charge/discharge efficiency of 75% or less when charged and discharged by employing metallic Li as a counter electrode; and the positive electrode contains a metal oxide (X) represented by AMeO(wherein A is Na and/or K, Me is Ni and/or Cu, x satisfies 1.9&#x2266;x&#x2266;2.1, and y satisfies 1.9&#x2266;y&#x2266;2.1).

Nonaqueous electrolytic solution secondary battery, and positive electrode and negative electrode used in the same

There is provided a negative electrode for a nonaqueous electrolyte secondary battery in which when a battery is formed, the energy density is high, and moreover, the decrease in charge and discharge capacity is small even if charge and discharge are repeated. By using silicon oxide particles having a particle diameter in a particular range as a starting raw material, and heating these particles in the range of 850&#xb0; C. to 1050&#xb0; C., Si microcrystals are deposited on the surfaces of the particles. Then, by performing doping of Li, a structure comprising a plurality of protrusions having height and cross-sectional area in a particular range is formed on the surfaces. The average value of the height of the above protrusions is 2% to 19% of the average particle diameter of the above lithium-containing silicon oxide particles. By using the lithium-containing silicon oxide particles obtained by the above means as a negative electrode active material, a negative electrode for a nonaqueous electrolyte secondary battery is fabricated.

Negative electrode for nanaqueous electrolyte secondary battery, nonaqueous electrolyte secondary battery using the same, and method for manufacturing negative electrode for nonaqueous electrolyte secondary battery

The object of an exemplary embodiment of the invention is to provide a negative electrode having excellent cycle property. An exemplary embodiment of the invention a method for doping and dedoping lithium for the first time after a negative electrode for a lithium secondary battery comprising silicon oxide as an active material is produced, comprising doping the lithium within the following current value range (A) and within the following doped amount range (B); current value range (A): a range of a current value in which a doped amount in which only one peak appears at 1 V or less on the V-dQ/dV curve becomes maximum, wherein the V-dQ/dV curve represents a relationship between voltage V of the negative electrode with respect to a lithium reference electrode and dQ/dV that is a ratio of variation dQ of lithium dedoped amount Q in the negative electrode to variation dV of the voltage V, and doped amount range (B): a range of a doped amount in which only one peak appears at 1 V or less on the V-dQ/dV curve.

Method for doping and dedoping lithium into and from negative electrode and method for producing negative electrode for lithium secondary battery

A secondary battery according to the present exemplary embodiment is a secondary battery including a laminated electrode body provided with at least one pair of positive and negative electrodes and an outer enclosure that accommodates the laminated electrode body, wherein the outer enclosure includes one or more concave portions, inside a border corresponding to an outer edge of an electrode surface of an outermost layer of the laminated electrode body, on a surface facing the electrode surface, and wherein, when a band-shaped outer circumferential region having an area that is a half of an area inside the border is set inside the border, at least one of the concave portions is located inside the outer circumferential region.

Secondary battery

There is provided a control system for a lithium secondary battery that can quantitatively sense a deterioration state inherent in a lithium secondary battery using silicon oxide as a negative electrode active material, that is, the nonuniform reaction state of a negative electrode. A control system for a lithium secondary battery including a positive electrode, a negative electrode using silicon oxide as a negative electrode active material, and a lithium reference electrode having a reference potential with respect to the negative electrode includes measurement means for measuring a voltage V of the negative electrode with respect to the lithium reference electrode and a discharge capacity Q of the lithium secondary battery during discharge of the lithium secondary battery; generation means for generating a V-dQ/dV curve representing a relationship between dQ/dV, which is a proportion of an amount of change dQ in the discharge capacity Q to an amount of change dV in the voltage V, and the voltage V; calculation means for calculating an intensity ratio of two peaks appearing on the V-dQ/dV curve for two voltage values in the voltage V; and sensing means for sensing a state of the negative electrode utilizing the intensity ratio.

Lithium secondary battery and control system therefor, and method for detecting state of lithium secondary battery

In a lithium ion secondary battery including a positive electrode, a separator, a negative electrode, and a package body, the negative electrode includes simple substance silicon as a negative electrode active material, and a negative electrode binder, and is doped with lithium, and the following formulas (1) and (2) are satisfied:1.2&#x2266;&#x2266;1.9&#x2003;&#x2003;(1)1.0&#x3c;/()&#x3c;1.6&#x2003;&#x2003;(2)wherein an amount of lithium inserted into the negative electrode until the negative electrode reaches a potential of 0.02 V with respect to metal lithium is M(a number of atoms), an amount of lithium released from the positive electrode until the positive electrode reaches a potential of 4.3 V with respect to metal lithium is M(a number of atoms), and an amount of lithium with which the negative electrode is doped is M(a number of atoms).

Lithium ion secondary battery and method for manufacturing the same

The disclosed device easily and precisely satisfies a requested output range, and is provided with: a &#x394;&#x3a3;-modulator () which converts a digital input signal to a pulse signal; an input comparison device () which compares an input value that corresponds to the digital input signal, and a pre-set threshold value; and a thinned output control unit () which, when the result of the comparison by the input comparison device () shows that the input value is less than the threshold value, reduces the output value corresponding to the input value in accordance with the size of the difference between the input value and the threshold value, and sets the output value to 0 when the input value is 0.

Modulator and &#x394;&#x3a3;-type D/A converter

In a constant current circuit, a constant current is caused to flow through a resistor, thereby causing a constant voltage to occur across the resistor. This constant voltage is then superimposed on an output signal of an operational amplifier that is to be fed back to the drain of a field effect transistor, thereby maintaining the same potential in an AC manner between the output terminal of the operational amplifier and the drain of the field effect transistor. In this way, the gate and drain of the field effect transistor is caused to exhibit the same potential in an AC manner, so that no current will occur through the stray capacitance between the gate and drain of the field effect transistor. As a result, similarly to a case of using a feedback capacitor, the input impedance of the field effect transistor can be raised.

Growing community of inventors

Tokyo, Japan

Tetsuya Kajita