Nano-vault architecture mitigates stress in silicon-based anodes for lithium-ion batteries
Marta Haro, Pawan Kumar, J. Zhao, Panagiotis Koutsogiannis, Alexander J. Porkovich, Zakaria Ziadi, Theodoros D. Bouloumis, Vidyadhar Singh, Emilio J. Juárez‐Pérez, Evropi Toulkeridou, K. Nordlund, Flyura Djurabekova, Mukhles Sowwan, Panagiotis Grammatikopoulos
Abstract
Abstract Nanomaterials undergoing cyclic swelling-deswelling benefit from inner void spaces that help accommodate significant volumetric changes. Such flexibility, however, typically comes at a price of reduced mechanical stability, which leads to component deterioration and, eventually, failure. Here, we identify an optimised building block for silicon-based lithium-ion battery (LIB) anodes, fabricate it with a ligand- and effluent-free cluster beam deposition method, and investigate its robustness by atomistic computer simulations. A columnar amorphous-silicon film was grown on a tantalum-nanoparticle scaffold due to its shadowing effect. PeakForce quantitative nanomechanical mapping revealed a critical change in mechanical behaviour when columns touched forming a vaulted structure. The resulting maximisation of measured elastic modulus (~120 GPa) is ascribed to arch action, a well-known civil engineering concept. The vaulted nanostructure displays a sealed surface resistant to deformation that results in reduced electrode-electrolyte interface and increased Coulombic efficiency. More importantly, its vertical repetition in a double-layered aqueduct-like structure improves both the capacity retention and Coulombic efficiency of the LIB.