摘要:
A lithium secondary battery comprises a natural graphite as a negative electrode capable of occluding and discharging lithium ion, in which the natural graphite has been heat treated at a temperature of from 2,400-3,000° C. The heat treatment removes impurities from natural graphite. As a result, the electrolyte solution used for the battery hardly decomposes during charge and discharge and self discharge hardly occurs during storage of the battery.
摘要:
The present invention provides a non-aqueous electrolyte secondary cell that has good high-temperature cycle characteristics and good high-temperature standing resistance, and that is highly safe enough to prevent overcharge. The non-aqueous electrolyte secondary cell of the invention utilizes a non-aqueous electrolyte that includes a vinylene carbonate derivative, a cyclic sulfite derivative, and both/either of a phenylcycloalkane derivative and/or an alkylbenzene derivative having a quaternary carbon directly bonded to a benzene ring.
摘要:
A non-aqueous electrolyte battery with improved cyclic characteristics and battery capacity at high temperature and capable of suppressing the evolution of gas during storage at high temperature while maintaining favorable cyclic performance, wherein vinylene carbonate (VC) and α-angelica lactone (4-hydroxy-3-pentenic acid γ-lactone) are contained in the electrolyte, and whereby a highly soft and flexible coating film with α-angelica lactone is formed on the surface of the negative electrode without reducing the initial charging efficiency of the battery. Since a mixed coating film comprising VC and α-angelica lactone is formed on the soft and flexible coating film and the mixed coating film has higher thermal stability at high temperature than that of the coating film formed only with VC, the cyclic characteristics of the battery at high temperature can be improved while enhancing the suppression of gas evolution during storage at high temperature.
摘要:
A secondary battery is comprised of a positive electrode, a negative electrode formed from a carbon composition intercalating lithium reversibly and a non-aqueous electrolyte. The non-aqueous electrolyte includes a lithium salt and a mixture of a low boiling point solvent having the boiling point of 150.degree. C. or lower and an organic solvent of vinylene carbonate or its derivative. The negative electrode may comprise a graphite, and the positive electrode may comprise a material being selected from a group consisting of metal chalcogen and metal oxide, such as V.sub.2 O.sub.5, TiS.sub.2, MoS.sub.2, LiCoO.sub.2, LiMnO.sub.2, LiNiO.sub.2, LiCrO.sub.2, LiMn.sub.2 O.sub.4 and LiFeO.sub.2. The low boiling point solvent may be selected from a group consisting of dimethyl carbonate, diethyl carbonate, 1,2-dimethoxy ethane, 1,2-diethoxy ethane and ethoxymethoxy ethane. The derivative may be provided by replacing at least one of two hydrogen atoms of the vinylene carbonate with one selected from a group consisting of a methyl group, an ethyl group and one halogen atom.
摘要:
Provided is a novel lithium secondary battery comprising a positive electrode comprising a compound capable of occluding and discharging lithium, a negative electrode composed mainly of a carbon material which comprises a graphite as an only or as a principal component, a separator between said positive electrode and said negative electrode; and an electrolyte solution of an electrolyte solute dissolved in a solvent comprising at least one specific cyclic compound. The lithium secondary battery has a large capacity, small self-discharge rate and excellent cycle characteristics and high charge-discharge efficiency.
摘要:
Provided is a novel lithium secondary battery including a positive electrode including a compound capable of occluding and discharging lithium, a negative electrode composed mainly of a carbon material which includes a graphite as an only or as a principal component, a separator between the positive electrode and the negative electrode; and an electrolyte solution of an electrolyte solute dissolved in a solvent including at least one specific cyclic compound.The lithium secondary battery has a large capacity, small self-discharge rate and excellent cycle characteristics and high charge-discharge efficiency.
摘要:
Provided is a novel lithium secondary battery including a positive electrode including a compound capable of occluding and discharging lithium, a negative electrode composed mainly of a carbon material which includes a graphite as an only or as a principal component, a separator between the positive electrode and the negative electrode; and an electrolyte solution of an electrolyte solute dissolved in a solvent including at least one specific cyclic compound. The lithium secondary battery has a large capacity, small self-discharge rate and excellent cycle characteristics and high charge-discharge efficiency.
摘要:
The invention provides a method for evaluating the safety of a battery under an internal short-circuit condition. The battery includes: an electrode group including a positive electrode, a negative electrode, and an insulating layer for electrically insulating the electrodes, which are wound or laminated; an electrolyte; a housing for housing the electrode group and the electrolyte; and a current-collecting terminal for electrically connecting the electrode group and the housing. The method of the invention includes: placing a foreign object at a location inside the electrode group of the battery where the positive electrode and the negative electrode face each other; and pressing the location by the pressure applied by a pressing tool to locally crush the insulating layer between the positive and negative electrodes, thereby causing an internal short-circuit. The contact area of the electrode group and the pressing tool during the pressing is larger than the area of a rectangle circumscribed about the foreign object. A short-circuit test is conducted at a given location inside the battery to comprehensively evaluate the safety of the battery under an internal short-circuit condition.
摘要:
OLT is provided with a field for storing the number of effective bits for searching ONU serial numbers, a field for storing a search start serial number and a field for storing a search end serial number, and ONU serial numbers are searched from the search start serial number to the search end serial number within the number of effective bits to automatically perform acquisition of the ONU serial number and ONU connection. An ONU automatic connection method for an ATM-PON system is provided by which an ONU serial number is searched efficiently without registering the ONU serial number from OpS to OLT.
摘要:
A leader tape where an non-magnetic under layer that contains a powder and a binder and a magnetic upper layer are sequentially laminated on at least one face of a support, in which F5 values of the support in a machine direction (MD) and in a transverse direction (TD) are from 80 to 120 MPa respectively, the F5 value in MD is larger than that in TD, and a difference between the F5 value in MD and that in TD is 15 MPa or less.