NOVELTY - An electrical device consists of a power-generating element comprising a positive electrode having a positive electrode active substance layer containing a positive electrode active substance and is formed on the surface of a positive electrode collector, a negative electrode having a negative electrode active substance layer containing a negative electrode active substance and is formed on the surface of a negative electrode collector, and a separator containing an electrolyte containing cyclic sulfonate ester.    USE - Electrical device e.g. nonaqueous electrolyte secondary battery such as lithium ion secondary battery (all claimed) for mobile telephone, portable apparatus, and power supply device of electric vehicles. Uses include but are not limited to hybrid vehicle, electric vehicle, and fuel cell electric vehicle.    ADVANTAGE - The electrical device has high output, capacitance, voltage and energy density.    DETAILED DESCRIPTION - An electrical device consists of a power-generating element comprising a positive electrode having a positive electrode active substance layer containing a positive electrode active substance and is formed on the surface of a positive electrode collector, a negative electrode having a negative electrode active substance layer containing a negative electrode active substance and is formed on the surface of a negative electrode collector, and a separator containing an electrolyte containing cyclic sulfonate ester. The positive electrode active material contains lithium nickel series complex oxide of insertable/detachable layered crystal structure for lithium ion and a composition of formula: (LiaNib)3a(NixMny-rMrCoz)3bO2, where M is titanium, zirconium, niobium, tungsten, phosphorus, aluminum, magnesium , vanadium, calcium, strontium, chromium, iron, boron, gallium, indium, silicon, molybdenum, yttrium, tin, vanadium, copper, silver and zinc, total content of x, y and z is 1 or less, b is 0.032 or less, sum of a and b is 0.9-1.2, x-z are 0-1, and r is 0-0.3. An INDEPENDENT CLAIM is included for nonaqueous electrolyte secondary battery.