Enhancing Interfacial Strength and Wettability for Wide-Temperature Sodium Metal Batteries.

Abstract

Development of high-performance sodium metal batteries (SMBs) with a wide operating temperature range (from -40 to 55°C) is highly challenging. Herein, an artificial hybrid interlayer composed of sodium phosphide (Na3 P) and metal vanadium (V) is constructed for wide-temperature-range SMBs via vanadium phosphide pretreatment. As evidenced by simulation, the VP-Na interlayer can regulate redistribution of Na+ flux, which is beneficial for homogeneous Na deposition. Moreover, the experimental results confirm that the artificial hybrid interlayer possesses a high Young's modulus and a compact structure, which can effectively suppress Na dendrite growth and alleviate the parasitic reaction even at 55°C. In addition, the VP-Na interlayer exhibits the capability to knock down the kinetic barriers for fast Na+ transportation, realizing a 30-fold decrease in impedance at -40°C. Symmetrical VP-Na cells present a prolonged lifespan reaching 1200, 500, and 500h at room temperature, 55°C and -40°C, respectively. In Na3 V2 (PO4 )3 ||VP-Na full cells, a high reversible capacity of 88, 89.8, and 50.3 mAhg-1 can be sustained after 1600, 1000, and 600 cycles at room temperature, 55°C and -40°C, respectively. The pretreatment formed artificial hybrid interlayer proves to be an effective strategy to achieve wide-temperature-range SMBs.