Today, lithium-ion batteries are the highest density electrical energy storage devices. They still bear the potential to be significantly improved by the application of new materials allowing higher voltages and capacities. In the long term, the development of reliable electric vehicles and the storage of electricity from renewables impose a step change in long term stability, energy density, safety, material sustainability as well as costs. However, a stepwise improvement of current Li-ion technology cannot hope to deliver. Thus, new approaches are required that can overcome current performance limitations. At the same time, these new strategies should avoid the use of scarce and expensive elements making batteries “greener” and cheaper. The envisioned applications that drive research on such improved batteries require both (i) high capacity and (ii) high (peak) rate capability. Here, we propose to explore new avenues that address exactly these characteristics and their fundamental scientific understanding. As a holistic approach we involve
a) high-capacity anode materials based on, e.g., Si-C, Sn-C, Ge-C nanocomposites. The alloying material should boost the capacity of the electrode while the carbon material will provide a stable electric contact, additional (fast) capacity and will form a stable solid electrolyte interphase (SEI).
b) high-voltage cathode materials taking advantage of Li phosphates including new ways of efficient electronic wiring.
c) multifunctional binders with the necessary improvements to allow exploiting the full potential of alloying materials.
d) new liquid electrolytes targeted at addressing the key challenges of alloying Li and Na batteries and high voltage intercalation materials. Particular attention is also put on solid-state Li and Na ion conducting electrolytes and in-depth understanding of alkaline insertion and transport parameters using impedance and NMR methods.
In combination, these contents may lead to a new generation of high performance batteries. To realize this interdisciplinary project a team with expertise in organic and inorganic chemistry, materials science and physical chemistry is brought together. The involved companies are able to turn the outcome of fundamental and application oriented research into real market solutions. The team has extensive experience in active material synthesis and characterization as well as with new electrolytes (liquid and solid) and their in-situ investigation of the all-important interfaces in the electrodes. In particular, the group is an internationally visible expert on alkaline ion mobility in both electrode materials and electrolytes which are complementarily studied by NMR and impedance spectroscopy. The combination with synthesis of novel materials and electrochemical investigations on energy materials makes the group one of the very rare European players using such complementary methods to characterize and develop new functional materials.