A scalable aluminum niobate anode for high energy, high power practical lithium-ion batteries

Abstract

Niobates are promising alternatives to commercial anodes like graphite and Li₄Ti₅O₁₂ (LTO), featuring high capacity, safe voltage and fast charging. Here, a comprehensive study at the material, electrode, and cell level is reported for a novel aluminum niobate (AlNb₁₁O₂₉, ANO) anode. Sub-micron ANO powder without surface modifications was synthesized in large quantities using a scalable sol–gel process and formulated into electrodes with practical active material loadings (89%). Compared with commercial-grade LTO, ANO delivered higher capacity at all C-rates up to 5C. When cycled at 0.5C, ANO retained 80% capacity for >450 cycles and ∼65% for >1000 cycles. High capacity (>2 mA h cm⁻²) ANO anodes were paired with commercial cathodes (LiCoO₂ and LiNi_0.8Co_0.15Al_0.05O₂) and high-voltage LiNi_0.5Mn_0.5O₄ in full cells with 0.9 N/P ratios and cycled at various C-rates, demonstrating performance scales well from the electrode to the cell level. For the first time, ANO full cell safety was studied and compared to LTO and graphite. Nail penetration of ∼2.5 W h pouch cells and charged electrode thermal imaging demonstrated that while charged ANO and LTO are more reactive in air, their high operating potential results in higher thermal stability compared to graphite electrodes in full cells.