Batteries, separators, electrodes, paints, battery pack, an electronic device, an electric vehicle, a power storage device and power system

The present invention improves the transparency of the particle-containing resin layer, batteries can manage its thickness with high precision, separator, electrode, paint, battery pack using these, electronic devices, electric vehicles, energy storage device and to provide a power system. Cells are those comprising a positive electrode, a negative electrode, an electrolytic solution and a particle-containing resin layer containing particles and a resin. The shape of particles comprise plane, and 40% or less than 100% plane of the particle, and the refractive index of the particles are less than 2.4 1.3 or more.