Section of Chemistry

Lithium-ion batteries

A lithium-ion battery is a member of a family of rechargeable battery types in which lithium ions move from the negative electrode to the positive electrode during discharge and back when charging. Li-ion batteries use an intercalated lithium compound as one electrode material, compared to the metallic lithium used in a non-rechargeable lithium battery. The electrolyte, which allows for ionic movement, and the two electrodes are the constituent components of a lithium-ion cell. 

Our research focuses on:

Electric Vehicle Batteries

Li-ion batteries of the type currently used worldwide in mobile-phones and lap-tops are, to a high degree of certainty, now poised also to become the battery of choice in future electric vehicle (EV) and hybrid electric vehicle (HEV) concepts, and other even larger-scale battery applications. This poses a number of new challenges within the Li-ion battery research field.

Current Li-ion batteries generally have Li cobalt oxide as their active cathode material. Upscaled Li-ion batteries must exploit a much cheaper transition-metal than cobalt (Co); ideally, the cheapest – iron (Fe) – in combination with a graphite (C)-based anode. This is the consequence of the hugely greater quantities of material needed in larger batteries. Whereas a mobile-phone battery consumes only a few grams of the relatively expensive active transition-metal oxide such as LiCoO2, an EV/HEV battery-unit will consume kilo-quantities of active cathode material per unit.

With larger quantities of battery materials, and using batteries in heavy vehicles at large speeds, there is also a need for increased battery safety. Side-reactions between the electrode and electrolyte materials must therefore be avoided.

Furthermore, while in operation, an EV or HEV battery has a considerably much faster charge-discharge cycle than conventional small-scale batteries normally have. Therefore, efforts are made to increase the cyclability and life-time of the battery materials.   

Our EV and large-scale battery research involve:

  • Development of a new iron silicate based active cathode materials (see cathodes).

  • Micro-cycling studies of battery materials.

  • Surface studies (XPS) of battery electrodes for improved safety and better material utilization.

  • Pilot-line Li-ion battery prototype production (financed by Knut and Alice Walleberg Foundation and the Swedish Energy Agency)

Networks

We participate in several networks with the Swedish vehicle industries and other academic partners; e.g., Swedish Hybrid Vehicle Centre, the Li-cluster and the Green Car Project. Internationally, we participate in the HELIOS project on EV batteries.