Lithium ion batteries (LIBs) are already an important part of our everyday life that have enabled the rise of portable electronics. Looking in the short-, middle-term, LIBs also hold tremendous potential to substitute the use of fossil fuels in transportation, with the still incipient Electric Vehicle (EV) market expansion . They have also found applications in decentralizing energy storage in residential areas, and they are being adopted for partially solving grid-unbalance issues caused by fluctuations in energy generation of renewable power sources . However, increasing the energy density of LIBs remains a primary challenge for enabling some of the aforementioned applications. Focusing on the anode side, graphite is the most used material, thanks to its low price and good cycling stability . Nevertheless, the maximum specific capacity that can be theoretically reached with graphite is 372 mAh/g, which limits the range of use cases for LIBs. In these regards, alloy negative electrodes, and in particular silicon (Si) , stands out as a promising candidate for next generation LIB anodes. When fully lithiated, Si forms the Li15Si4 alloy, showing a high theoretical specific capacity of 3579 mAh/g, ten times larger than graphite.