Transformative Binder-Free Strategy Shatters 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 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 Zn0.5Mg0.5Mn2O4 (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 5 C, 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 0.1 C and excellent rate capability up to 10 C (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 LiNi1/3Mn1/3Co1/3O2 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.