Dynamic Regulation of Lithium Dendrite Growth with Electromechanical Coupling Effect of Soft BaTiO3 Ceramic Nanofiber Films

Lithium (Li) metal batteries (LMBs) offer great opportunity for developing high- energy density energy-storage-systems, but the anodes suffer a severe problem of dendrite growth that hinders the practical applications of LMBs. Here, we report a soft BaTiO3 ceramic nanofiber film with excellent ferroelectricity and piezoelectricity that enables one to transverse the dense deposition of Li metal. During Li plating, the strong ferroelectricity reduces the Li-ion concentration gradient near the anode and thus facilitating their uniform deposition. Once squeezed by these Li deposits, the BaTiO3 film generates instantaneous piezo-effect to dynamically change the subsequent Li deposition from vertical to lateral. As a result, Li-Cu cells exhibit reversible plating-stripping processes for over 200 cycles with a high Coulombic efficiency of >98.3%. When pairing with high-voltage LiNi0.8Co0.15Al0.05O2 cathodes, the LMBs can retain >80% capacity in 300 cycles without forming dendrites even under challenging conditions including a high cathode loading of 7.2 mg/cm(2), a lean electrolyte amount of 7 mu L/mg, and high current rates. The findings point to a promising electromechanical coupling strategy to dynamically adjust dendrite growth for designing Li metal anodes.

Automated summary

A soft BaTiO3 ceramic nanofiber film with excellent ferroelectricity and piezoelectricity is reported for regulating the deposition of Li metal, addressing the issue of dendrite growth in lithium metal batteries. Experimental results demonstrate that Li-Cu cells using this film exhibit high Coulombic efficiency over 200 cycles, while LMBs paired with high-voltage cathodes maintain 80% capacity in 300 cycles.