A lithium battery includes a positive electrode plate, a negative electrode plate, an electrolyte disposed between the positive electrode plate and the negative electrode plate, a separator disposed in the electrolyte, and an organic-inorganic composite film disposed on the surface of the positive electrode plate, the surface of the negative electrode plate, the surface of the separator, or a combination thereof. The organic-inorganic composite film includes 100 parts by weight of clay, 3 to 35 parts by weight of lignocellulose, and 25 to 270 parts by weight of a first binder.