Integration issues of lithium-ion battery into electric vehicles battery pack

The critical challenges to enlarge the market share of electric vehicles (EVs) are cost, performance, reliability and safety. These issues are closely linked to the energy storage system in the EVs. Lithium-ion batteries have revolutionized the EV industry to become the preferred battery choice for EVs. This is due to their outstanding characteristics including high energy density, high voltage, low self-discharge rate, long cycle life, high charging and discharging rate capability. In EVs, Lithium-ion cells are connected in series and/or parallel to deliver the required power to the traction motor and auxiliary systems. However, due to the operating environment of EVs, the Lithium-ion battery may not perform to the best of its ability when integrated into an EV battery pack. In this work, the integration of Lithium-ion battery into an EV battery pack is investigated from different aspects, namely different battery chemistry, cell packaging, electric connection and control, thermal management, assembly and service and maintenance. In addition, benchmarking study using different cell packaging of Lithium Iron Phosphate cell as an energy storage system is conducted. This study provides a basic guideline for cell selection and integration of cell for the EVs battery pack.