Transformative binder-free strategy breaks cyclability limits for high-energy density oxide anode-based lithium-ion batteries

Abstract

This work presents a facile and effective binder-free fabrication strategy to overcome the primary limitations of conversion-based anodes for lithium-ion batteries (LIBs). By employing the electrophoretic deposition (EPD) technique, we directly assemble multi-metal oxide nanofibers on the current collector, creating an integrated electrode architecture that eliminates inactive binders and promotes superior charge transfer. This binder-free approach enables remarkable electrochemical performance in spinel Zn_0.5Mg_0.5Mn₂O₄ (ZMMO-0.5) nanofibers, most notably achieving ultra-stable cycling with a capacity of 186 mAh g⁻¹ after 2000 cycles at a high rate of 5C, a result that significantly surpasses most reports on conversion-type anodes. The anode also delivers a high initial specific capacity of 947 mAh g⁻¹ at 0.1C and excellent rate capability up to 10C (108 mAh g⁻¹). The enhanced stability is rooted in the material's design, where the synergistic interplay between a Li-alloying element (Zn) and a stabilizing MgO matrix preserves the integrity of the electrode during repeated conversion and alloying–dealloying reactions. Demonstrating its practical potential, a full-cell featuring the binder-free ZMMO-0.5 anode and a binder-free LiNi_1/3Mn_1/3Co_1/3O₂ cathode achieves a competitive gravimetric energy density of 180 ± 3 Wh kg⁻¹. These results highlight the pivotal role of binder-free electrode design in advancing high-capacity, long-life LIBs.