Porous silicon-based anode materials have gained much interest because the porous structure can effectively accommodate volume changes and release mechanical stress, leading to improved cycling performance. Magnesiothermic reduction has emerged as an effective way to convert silica into porous silicon with a good electrochemical performance. However, corrosive HF etching is normally a mandatory step to improve the electrochemical performance of the as-synthesized silicon, which significantly increases the safety risk. This has become one of the major issues that impedes practical application of the magnesiothermic reduction synthesis of the porous silicon anode. Here, a facile HF-free method is reported to synthesize macro-/mesoporous silicon with good cyclic and rate performance by simply increasing the reduction temperature from 700 °C to 800 °C and 900 °C. The mechanism for the structure change resulting from the increased temperature is elaborated. A finite element simulation indicated that the 3D continuous structure formed by the magnesiothermic reduction at 800 °C and 900 °C could undertake the mechanical stress effectively and was responsible for an improved cyclic stability compared to the silicon synthesized at 700 °C.

Sulfide-based solid electrolytes (SEs) are promising enablers of next-generation solid-state batteries (SSBs), yet their practical implementation is limited by interfacial instability with anode and cathode active materials. Current interfacial mitigation strategies rely primarily on inorganic coatings, which are often unable to accommodate chemo-mechanical strain. Here, we introduce a new dynamic ion gel nanocoating that stabilizes both cathode and anode interfaces in sulfide-based SSBs. It is a type of ion-conductive polyelectrolyte complex (PEC), which is formed via complex coacervation between oppositely charged polyelectrolytes. Controlled mixing of a polycation bearing ammonium groups with TFSI– counteranions and a polyanion featuring pendant TFSI– groups with Li+ countercations yields a homogeneous, solution-processable dynamic ion gel accompanied by LiTFSI release. This enables uniform, thin (≈1–3 nm), and scalable PEC nanocoatings on active material particles via spray drying. Dynamic ionic cross-linking endows the PEC with enhanced viscoelasticity and improved ionic conductivity relative to the parent polycation, allowing it to adapt to solid–solid interfaces while maintaining efficient ion transport. SSBs employing PEC-coated silicon anodes and PEC-coated LiNiO2 cathodes exhibit improved cycling stability through suppression of interfacial side reactions. Thus, the PEC nanocoating acts as a scalable stabilizer of solid–solid interfaces in SSBs.