SPIDER - Safe and prelithiated high energy density Batteries based on Sulphur Rocksalt and Silicon Chemistries

As part of the EU research project "SPIDER", the TU Munich, Institute for Machine Tools & Industrial Management (iwb) and 13 other European re-search institutions and companies are researching a new generation of lithium-ion cells. The consortium is working on the development and production of a more cost effective, more powerful, longer-lasting and safer battery technology to enable faster market penetration of electric vehicles and the reduction of CO2 emissions. For this purpose, SPIDER technology combines high performance/cost effective active materials, prelithiation and intrinsically safe liquid electrolyte formulations.

Project Description

The demand for electric vehicles is growing rapidly. McKinsey estimates that by 2030 the share of electric vehicles and plug-in hybrids could rise to nearly 20 % of annual global automotive sales (nearly 35 % of European sales). Electrification is seen as a great opportunity to significantly improve mobility, mitigate climate change and improve air quality. However, in order to increase the acceptance of electric vehicles, further measures such as cost reduction, increased range, increased safety and shorter charging times are needed. The development of significantly improved materials is an important aspect here.
SPIDER's main objective is therefore to develop a powerful, durable and safe lithium-ion battery technology based on four key innovations:

•  New high capacity cathodes, sustainable and cost effective, based on rock salt materials to achieve an energy density of 1000 Wh/kg at material level. The total energy of these cathodes provides unprecedented specific energy compared to current materials such as NMC 622 (200 mAh/g). In addition, these disruptive cathode materials are free of critical raw materials (Co) and less expensive than conventional technologies.

• High-capacity silicon-carbon composite anodes with capacities of up to 1500 mAh/g make it possible to increase the energy density of the cell by adjusting the silicon content. In addition, natural graphite, which is also a critical raw material, is partially replaced by silicon (obtained from non-critical alloys) in these anode materials. The amount of graphite can thus be reduced by up to 80 %.

• One of the main ageing mechanisms in lithium-ion batteries is the loss of cyclic lithium due to the instability of the solid electrolyte interphase (SEI). In order to counteract this effect and thus increase the cyclic stability, a prelithiation process is developed and applied to build up an additional lithium reservoir within the cell.

• The use of modified electrolyte compositions, which remove combustible electrolyte components and thus significantly increase battery safety.

The main tasks of the iwb in the project network are the development of a suitable prelithiation method, its upscaling and the techno-economic evaluation of various prelithiation methods.

ACKNOWLEDGEMENT

This research project is funded by the European Commission under the Horizon 2020 research and innovation programme (Grant No. 814389). We would like to thank the European Commission for its funding and support in the realisation of the project. The author is responsible for the content of this publication.