A negative active material for a rechargeable lithium battery includes a core including a SiO.sub.2 matrix and a Si grain, and a coating layer continuously or discontinuously coated on the core. The coating layer includes SiC and C, and the peak area ratio of the SiC (111) plane to the Si (111) plane as measured by X-ray diffraction analysis (XRD) using a CuKα ray ranges from about 0.01 to about 0.5.

An object is to provide a nonaqueous electrolyte and a nonaqueous-electrolyte secondary battery which have excellent discharge load characteristics and are excellent in high-temperature storability, cycle characteristics, high capacity, continuous-charge characteristics, storability, gas evolution inhibition during continuous charge, high-current-density charge/discharge characteristics, discharge load characteristics, etc. The object has been accomplished with a nonaqueous electrolyte which comprises: a monofluorophosphate and/or a difluorophosphate; and further a compound having a specific chemical structure or specific properties.

Here is described an aluminum-ion battery technology having an electrolyte comprising an aluminum trichloride (Al—Cl3)/trimethylamine hydrochloride ionic liquid, aluminum metal as the anode material, and a compatible cathode active material. A wide variety of applications ranging from energy storage in consumer electronics to electric vehicles and to grid storage is also considered.

A negative active material for a rechargeable lithium battery includes a core including a SiO.sub.2 matrix and a Si grain, and a coating layer continuously or discontinuously coated on the core. The coating layer includes SiC and C, and the peak area ratio of the SiC (111) plane to the Si (111) plane as measured by X-ray diffraction analysis (XRD) using a CuKα ray ranges from about 0.01 to about 0.5.

Described herein are liquid, organosilicon compounds that including a substituent that is a cyano (—CN), cyanate (—OCN), isocyanate (—NCO), thiocyanate (—SCN) or isothiocyanate (—NCS). The organosilicon compounds are useful in electrolyte compositions and can be used in any electrochemical device where electrolytes are conventionally used.

A metal-ion battery includes: (1) an anode including aluminum; (2) a cathode including a layered, active material; and (3) an electrolyte disposed between the anode and the cathode to support reversible deposition and dissolution of aluminum at the anode and reversible intercalation and de-intercalation of anions at the cathode.

Provided is a binder composition for a non-aqueous secondary battery electrode that can form a slurry composition for a non-aqueous secondary battery electrode having excellent viscosity stability and a non-aqueous secondary battery having excellent cycle characteristics. The binder composition for a non-aqueous secondary battery electrode contains: a polymer that includes a monomer unit including a functional group that is bondable with a cationic group and a (meth)acrylic acid ester monomer unit; and an organic compound that includes at least two cationic groups. The binder composition for a non-aqueous secondary battery electrode has a viscosity change rate of 400% or less when left at rest at a temperature of 60° C. for 30 days.

A rechargeable lithium cell comprising a cathode, an anode, an optional ion-permeable membrane disposed between the anode and the cathode, a non-flammable salt-retained liquefied gas electrolyte in contact with the cathode and the anode, wherein the electrolyte contains a lithium salt dissolved in or mixed with a liquefied gas solvent having a lithium salt concentration greater than 1.0 M so that the electrolyte exhibits a vapor pressure less than 1 kPa when measured at 20° C., a vapor pressure less than 60% of the vapor pressure of the liquefied gas solvent alone, a flash point at least 20 degrees Celsius higher than a flash point of the liquefied gas solvent alone, a flash point higher than 150° C., or no flash point, wherein the liquefied gas solvent is selected from methane, fluoromethane, difluoromethane, chloromethane, dichloromethane, ethane, fluoroethane, difluoroethane, tetrafluoroethane, chloroethane, dichloroethane, tetrachloroethane, propane, fluoropropane, chloropropane, ethylene, fluoroethylene, chloroethylene, or a combination thereof.

An electrolyte for a rechargeable lithium battery includes an organic solvent including C3 to C5 alkyl propionate, and the electrolyte further includes a lithium salt and a compound represented by Chemical Formula 1,

##STR00001## wherein, in Chemical Formula 1, k, l, and m are independently integers of 0 to 20, k, l, and m are selected, so that Chemical Formula 1 has an asymmetric structure, n is an integer of 1 to 7, and R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, and R.sup.6 are independently hydrogen, an alkyl group, an alkoxy group, or a fluoroalkyl group.

An electrolyte for a lithium-ion battery which includes lithium hexafluorophosphate and lithium 2-pentafluoroethoxy-1,1,2,2-tetrafluoroethanesulfonate. A lithium-ion battery which includes an electrolyte containing lithium hexafluorophosphate and lithium 2-pentafluoroethoxy-1,1,2,2-tetrafluoroethanesulfonate. A motor vehicle which uses a lithium-ion battery having electrolytes containing lithium hexafluorophosphate and lithium 2-pentafluoroethoxy-1,1,2,2-tetrafluoroethanesulfonate. The electrolyte can increase the service life of the lithium-ion battery.