Manipulating oriented crystal growth of Zn via lattice-matched and zincophilic MXene nanoarrays towards dendrite-free Zn batteries

Abstract

Though aqueous Zn-ion batteries have garnered significant attention and extensive research due to their merits of high safety and excellent electrochemical performances, the disadvantages of Zn anodes including uncontrollable dendrite growth, interfacial corrosion, and side reactions seriously restrict their practical applications. Herein, lattice-matched and zincophilic MXene nanoarrays are introduced to enable dendrite-free Zn anodes. The Ti₃C₂T_X MXene with a low curvature interface shows high lattice matching (90 %) with the (0 0 2) plane of Zn, manipulating the oriented crystal growth of Zn (0 0 2) on MXene. In addition, MXene reveals a high adsorption energy of the Zn atoms, decreasing the Zn nucleation barrier and further promoting the uniform Zn nucleation. Moreover, the MXene nanoarray exhibits abundant interspaces and exceptional electrical conductivity, which accelerates Zn²⁺ ion transport and electron conduction, eliminating the ion concentration gradient and homogenizing the interfacial electric field distribution at the anode surface. Consequently, the MXene substrate achieves a high average Zn utilization of 97.9 % over 350 cycles, and the MXene-Zn anode demonstrates a long cycle life of more than 1100 h with a remarkably low voltage hysteresis of 15.7 mV at 1 mA cm⁻². Furthermore, MXene-Zn||MnO₂ cells display a high capacity retention of 80.2 % after 1600 cycles at 2 A g⁻¹.