Method and system for determining service life attenuation of lithium ion battery energy storage power station

The invention relates to a method and a system for determining life attenuation of a lithium ion battery energy storage power station. The method comprises the following steps: acquiring an annual electricity abandoning curve of a year-by-year i between a planning target year and an initial year of a planned power grid and a year I needing to be calculated; obtaining planning basic parameters of the lithium ion battery energy storage power station; calculating the effective capacity of the energy storage power station in the initial year; determining the abandoned electric quantity of the ith year; calculating the annual equivalent cycle index of the ith year of the energy storage power station; calculating the annual effective capacity of the ith year of the energy storage power station; calculating the annual average capacity attenuation rate of the ith year of the energy storage power station; and if i is smaller than or equal to the year I required to be calculated, making i = i + 1, and repeating the ste