The invention relates to a composition which comprises LiPF6 crystals and water, the particle size distribution of the LiPF6 crystals is uniform, the particle size of 35-50% of the crystals is largerthan or equal to 0.2 mm and smaller than 0.25 mm, the particle size of 35-50% of the crystals is larger than or equal to 0.25 mm and smaller than or equal to 0.3 mm, and the water content is lower than 8 ppm. The product disclosed by the invention is high in stability, high in consistency, high in purity and low in moisture content, and a lithium ion battery prepared by using the product as an electrolyte component is excellent in performance.