Discharge characteristics of multicell lithium-ion battery with nonuniform cells

Abstract

This paper addresses the discharge characteristics of a multicell lithium-ion battery with nonuniform cells. By using a multicell battery with two different types of cell, we experimentally investigate the relationship between discharge capacity and battery topology. In the series connection of nonuniform cells, the total capacity of the battery is governed by a cell with the smallest capacity. In the parallel connection, the total capacity becomes the sum of cells in parallel. In a multicell battery with the series–parallel connection, the discharge capacity depends on its configurations such as connection and number of nonuniform cells. Also, we derive a mathematical model for discharge characteristics of the multicell battery based on the equivalent circuit model of an individual cell. For a multicell battery with a general configuration, the discharge capacity is successfully evaluated by numerical simulations of the mathematical model.