The project aims at developing eco-friendly negative electrodes for Li-ion batteries by using water-based
deposition techniques. To that aim, all materials must be water-compatible: they should (i) not react with water,
(ii) be easily dispersible in the water/binder mix to form a homogeneous coating and (iii) keep their cycling
properties once processed as electrode.
Negative electrode materials and conductive additives will be carbon-coated using low-temperature
plasma (ICS). Silicon (Ferroglobe) and titania (TioTech) will be used as active
materials. Conductive additives will be commercial carbon blacks and nanotubes. Electrodes will be
prepared via a water-based process and their electrochemical performances will be assessed (ULiège). If
successful, the overall strategy should be applicable to positive electrodes.
Besides environmental impacts, replacement of organic solvents by water should also lead to significant decrease in electrode processing costs.
The battery market is expected to drastically increase in the next few years, given the demand for electrical energy storage in vehicles, for stationary applications and for small electronics. According to the European Battery Alliance (www.eba250.com), the global market should reach 250 G€/year by 2025. However, this huge deployment requires the development of new materials and manufacturing processes, to make sure that batteries consist in sustainable energy storage systems and do not become another environmental issue. To that aim, the project aims at modifying emergent Li-ion battery materials in order to (i) make them compatible with a water-based manufacturing process, (ii) increase their global performance in electrode configuration by improving the dispersion of the conductive additive, (iii) increase their lifetime upon cycling, (iv) facilitate their end-of-life recycling by avoiding the use of fluorinated binders that are hard to separate from the other components.
Within the project, an existing low-temperature plasma coating process will be adapted to coat Li-ion battery active materials and conductive additives with a thin carbon layer that can further be functionalized. Si and TiO2 will be used as battery anode materials. Since electron conductivity is key to the final electrode performance, conductive additives will be coated as well so as to improve their dispersibility in water and, therefore, the homogeneity of their distribution within the final electrode. The coatings will be thoroughly characterized and the powder properties evaluated by all partners vs. their uncoated counterparts. Finally, ULiège will deposit the materials onto current collectors using a versatile spray-coating water-based process; the obtained electrodes will be assembled as coin-cell and pouch-cells to assess the electrochemical properties of the materials for use in Li-ion batteries.