Nowadays, there is world-wide interest in more efficient systems for energy storage and the replacement of internal combustion engines by hybrids or full electric vehicles. Lithium ion batteries (LIBs) can make a remarkable contribution to the above if they reach the technological level needed for their use as batteries in electric vehicles. Porous silicon (PSi) is one of the most promising materials to be used as a component in anodes in LIBS mainly because of its ability to storage large amounts of lithium ions and its large electrolyte-accessible surface area. Although there are a variety of methods for PS formation, in terms of costs, only metallurgical Si (MG-Si) as a precursor for porous formation can be comparable to the traditional graphite used as anode, which has to be replaced because of its limited properties. Traditionally, metal nanoparticles such as Ag, Au, Pd, and Pt have been used in porous formation mainly due to its capacity for drilling the silicon wafer via electrochemical etching. However, because of its origin, MG-Si contains many more impurities than silicon wafer and also, as a powder, electrochemical etching cannot be used. Therefore, for the first time this project proposes an electroless etching method catalyzed by silver and copper nanoparticles for MG-Si porosification. Copper NPs are low-cost materials that under appropriate conditions can crack the Si surface thereby taking advantage of the impurities present, and thus, they may contribute to the MG purification. In addition, as a consequence of the low electric conductivity of PSi, conductor electrical metal nanoparticles can be incorporated within PSi, since they may contribute to improving the properties of carbon-based materials traditionally used for improving the electrical contact in the anode. As a result, it is expected that the PSi composite fabricated under optimized processing conditions can significantly improve battery performance.
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