The development of larger, more efficient, cheaper, safer and necessarily “greener” Li-ion batteries (LIBs) for electric vehicle (EV) and especially stationary energy-storage applications continues to present a major challenge to battery researchers and developers the World over. There are several underlying reasons for this; not least, the availability and cost of appropriate raw materials.  For example, several millions of tons/year of active cathode material will be needed if we are to achieve the long-term goal of a worldwide transition from ICEs to EVs – and to realistically cheap LIBs for use in large-scale sustainable-energy storage applications.    

     In this context, the absence of an ideal CATHODE material with a sufficiently high energy-density is arguably the most serious bottleneck facing us. A significant breakthrough has come with the development of polyanion-based cathode materials; typically, phosphates and silicates: e.g., LiFePO₄ [1] and Li₂FeSiO₄ [2]. These materials are expected to be both cheaper and safer than conventional LIB transition-metal oxide cathode materials. A negative feature of these materials is, however, their poor electronic conductivity – a problem which is normally addressed by reducing particle-size into the nano-range and promoting ion conductivity through the use of various particle-surface coatings. Arguably the most promising cathode materials for large-scale applications involve the Li-M-SiO₄ family of silicates, typically Li₂FeSiO₄.

    We present here an account of our recent advances in addressing the challenge of scaling up our successes on a lab-scale to produce well-functioning Li₂FeSiO₄ vs. graphite full-cell prototypes suitable for the sustainable energy storage market.

Keywords: lithium-ion battery, cathode material, scale-up, EV, sustainable-energy storage

REFERENCES                                                                            

[1]  A.K. Padhi et al., J. Electrochem. Soc., 144, 1609 (1997).

[2]  A. Nytén et al., Electrochem. Commun., 7, 156 (2005).

ACKNOWLEDGEMENTS

This work has been supported by the Global Climate and Energy Project of Stanford (GCEP), the Swedish Energy Agency (STEM), VINNOVA and the Swedish Science Research Council (VR).