Mitsubishi Denki Kabushiki Kaisha

Other

Jun Aragane

Hisashi Shiota

Daigo Takemura

Hiroaki Urushibata

Shigeru Aihara

Makiko Kise

Yasuhiro Yoshida

Kouji Hamano

Takashi Nishimura

Michio Murai

Takayuki Inuzuka

Shoji Yoshioka

Syoji Yoshioka

Osamu Hiroi

Hisashi Tsukamoto

Kenji Kawaguchi

Masaharu Moriyasu

Hideo Horibe

Hideo Ichimura

Shinji Nakadeguchi

Hironori Ozaki

Hiroshi Adachi

Hironori Kuriki

Sei Tsunoda

Sigeru Aihara

Conventional batteries are disadvantageous in that a firm outer case must be used to maintain an electrical connection between electrodes, which has been an obstacle to size reduction. Those in which each electrode and a separator are joined with an adhesive resin suffer from conflict between adhesive strength and battery characteristics, particularly ion conductivity and internal resistivity. To solve these problems, it is an object of the invention to reduce resistance between electrodes, i.e., internal resistance of a battery to improve battery characteristics while securing both insulation function against electron conduction and ion conductivity between electrodes and also to maintain adhesive strength enough to firmly join the electrodes thereby to provide a light, compact and thin battery. The internal resistivity can be diminished by joining a positive electrode and a negative electrode with an adhesive resin layer having at least one adhesive resin layer containing a filler. The adhesive resin layer has pores, which are filled with an electrolytic solution to exhibit sufficient ion conductivity thereby to improve battery characteristics and to retain adhesive strength.

Battery with adhesion resin layer including filler

Conventional batteries have the problem that, when battery temperature rises above a temperature at which the separator melts and flows due to an internal short-circuit, a large short-circuit current is generated between the positive and negative electrodes, that further raises the battery temperature. As a result, the short-circuit current further increases. The inventive electrode increases its resistivity with increasing temperature, and a processing for producing the electrode is disclosed. The electrode of the invention has an electron conductive material containing a conductive filler and a resin and increases its resistivity with increasing temperature.

Process for producing an electrode with positive temperature coefficient (PTC) function

Conventional separators had a function that their melting made minute holes inside the separator smaller, leading to cut off of ion conductivity in temperature increase due to unusual conditions such as short circuit. However, there was a problem that, at a temperature higher than a certain degree, not only the minute holes were closed but also the separator itself was melted to cause deformation of the separator such as shrink and generation of holes due to melting and insulation was broken. The present invention has been carried out in order to solve the above problems. The separator for batteries of the present invention comprises a first porous layer ( ) containing a thermoplastic resin as a main component and a second porous layer ( ) laminated on the first porous layer ( ), which has higher heat resistance than that of the first porous layer ( ).

Separator for battery and battery

The battery of the present invention comprises the electrode which contains the pre-determined amount of electronically conductive material at which resistance increases in accordance with temperature rise and conductive agent; the electrode wherein the ratio of the total amount of the electronically conductive material and the conductive agent to the active material is set to a pre-determined value; and the electrode wherein the average particle size of the conductive agent based on the average particle size of the electronically conductive material is in a pre-determined range. The coducitive material contains an electrically conductive filler and a crystalline resin. The conductive material and the coductive agent are contacted with the active material. A significant reduction in short circuit current is achieved over a defined range of conductive agent particle size.

Battery and electrode including an active material, an electrically conductive material and a conducting agent

A method for manufacturing a lithium ion secondary battery comprising preparing a positive electrode ( ) where a positive electrode active material ( ) is joined with a positive electrode collector ( ), a negative electrode ( ) where a negative electrode active material ( ) is joined with a negative electrode collector ( ), and a separator ( ) for retaining the electrolytes including lithium ions, being arranged between the positive electrode ( ) and the negative electrode ( ), the process of supplying adhesive solution applied on the separator with a second solvent different from a first solvent after applying the adhesive resin solution, where adhesive resin ( ) is dissolved in the above first solvent, to the separator ( ), and the process of forming an electrode laminate by sticking the positive electrode ( ) and the negative electrode ( ) to the separator ( ).

Method for manufacturing lithium ion secondary battery

Conventional batteries have a problem that, in case the battery temperature should rise to 100&deg; C. or higher due to an internal short-circuit, etc., a large short-circuit current develops to generate heat. It follows that the battery temperature further increases, which can result in a further increase of the short-circuit current. Further, some of electrode structures involve reduction in discharge capacity. These problems are solved by a battery in which an electron conductive material ( ), being in contact with an active material ( ) in an electrode, comprises a conductive filler and a resin so that the electrode may increase its resistivity with a temperature rise, and the ratio of the particle size of the electron conductive material ( ) to that of the active material ( ) is in a range of from 0.1 to 20.

Cell and method of producing the same

A conventional battery has a problem that a large short-circuit current was generated with temperature rise due to internal short-circuit or the like, and therefore, the temperature of the battery further increases due to exothermic reaction to increase the short-circuit current. The present invention has been carried out in order to solve the above problems. The battery of the present invention is a battery wherein at least one of a positive electrode and a negative electrode comprises an active material layer containing an active material and an electronically conductive material contacted to the active material , wherein a solid electrolytic layer is interposed between the above positive electrode and the negative electrode , and wherein the above electronically conductive material comprises an electrically conductive filler and a resin so that resistance increases with temperature rise.

Battery and process for preparing the same

The object of the present invention is to obtain an electrode whose resistivity increases with temperature, and a battery using the same. Specifically, the invention consists in limiting the proportion of a conductive filler contained in electron conductive particles of an electron conductive particle layer to a range of from 55 to 70 parts by weight. A battery constituted by using the electrode has an increased discharge capacity and is capable of reducing a short-circuit current.

Electrode having PTC function and battery comprising the electrode

A battery with an active material layer having an active material an electronically conductive material contacted to the active material and an electrolytic layer jointed with the active material layer wherein the electronically conductive material comprises an electrically conductive filler and a resin having a predetermined thermal melting temperature T and has a Positive Temperature Coefficient (PTC) such that resistance of the electrically conductive material increases with temperature, and wherein the active material layer and the electrolytic layer are laminated and are jointed together by heating the resin to a predetermined thermal treatment temperature T

A battery body, which is composed of a laminated body obtained by laminating a cathode and an anode via a separator or a wound body obtained by winding them in a laminated structure and a plurality of leads connected to the cathode and the anode, is contained in a flexible package, and after an electrolyte solution is injected thereinto, an opening of the package is sealed at pressure which is lower than atmospheric pressure and is reduced to not less than vapor pressure of the electrolyte solution so that a thin battery is fabricated. A rise in pressure in the battery due to generation of gas in the battery and volume expansion of the gas can be restrained when the battery is maintained at high temperature.

Thin battery and method of manufacturing

A battery package including laminate sheets adhered each other along their peripheral to form a container portion for receiving an electrode assembly and a seal portion. The seal portion surrounds the container portion and protrudes outwardly from side faces of the container portion. The seal portion has enough width to maintain the container portion free from moisture for long periods of time. The laminate sheets include a heat-adhesive polymer layer and a metal layer which stops moisture and provides a shape-maintaining ability to the laminar sheets. The seal portion is folded or curled to reduce a projection area of the battery package.

Battery package

An adhesive for batteries. The adhesive has improved wetting properties, improved adhesive strength and prevents deterioration of battery performance. Secondary batteries can be obtained having an arbitrary shape such as a thin shape with high reliability and high charge and discharge efficiency. The adhesive includes a thermoplastic resin, a solvent capable of dissolving the resin and a neutral and aprotic surfactant. The surfactant includes a polysiloxene skeleton. The adhesive is used in batteries for adhering an active material layer joined to a current collector to a separator.

Bonding agent for cells and cell using the same

A lithium ion secondary battery having an electrode body including a positive electrode made of a positive electrode active material layer joined to a current collector, a negative electrode made of a negative electrode active material layer joined to a current collector, a separator which is disposed between the positive electrode and the negative electrode and retains an electrolytic solution containing lithium ions, and a porous adhesive resin layer which retains the electrolytic solution and joins the separator to at least one of the positive electrode active material layer and to the negative electrode active material layer, the electrode body being sealed into a packaging bag, wherein an adhesive resin film capable of absorbing the electrolytic solution and gelling adheres the electrode body to the packaging bag.

Growing community of inventors

Tokyo, Japan

Jun Aragane