Lithium-ion batteries: Experimental research and application to battery swapping stations

Abstract

Wider adoption of electrical vehicles (EVs) is mainly governed by the battery technology which is still unable to provide driving comfort (and expenses) of conventional internal combustion engine vehicles. The paper is concerned with experimental research of lithium-ion rechargeable batteries, with the aim to improve operation of battery swapping stations (BSSs), a concept that represents an alternative to the EV charging stations. The paper provides insight into the EV charging, concept of BSS, rechargeable batteries (terminology, technology and attributes), and lithium-ion battery charging procedure (constant-current-constant-voltage). For the purpose of investigating charging/discharging characteristics of various batteries, an advanced bidirectional AC-DC converter has been developed. The converter is presented, along with the experiments which proved its functionality. Experiments are conducted on a lithium-ion battery cell by charging/discharging with different currents. Various battery characteristics are obtained and application of results to BSSs is discussed.