Promoting ion adsorption and desolvation kinetics enables high capacity and rate capability of stibium anode for advanced alkaline battery

Abstract

• A nitrogen doped carbon is fabricated as substrate for high capacity and high rate Sb anode in alkaline electrolyte. • The deposition chemistry and failure mechanism of Sb anode is proved as highly related to the adsorption and desolvation of [Sb(OH) 4 ] − . • The Ni-Sb full batteries based on NCNs substrate exhibit high areal capacity and excellent rate capability. Stibium (Sb) metal with high theoretic capacity, suitable negative working window and inexpensive nature are promising anode material for advanced aqueous alkaline batteries (AABs). However, the further development of Sb anode is severely hindered by the low capacity and poor rate capability which is originated from deficient adsorption of [Sb(OH) 4 ] − and its sluggish desolvation kinetics. Herein, a nitrogen doped carbon cages (NCCs) substrate is constructed as high capacity and rate capability anode by promoting the adsorption and following desolvation process of [Sb(OH) 4 ] − via the enhanced attraction toward (OH) − in the solvated [Sb(OH) 4 ] − . Consequently, the designed Sb/NCCs anode delivers a high capacity of 627 mAh g −1 with an average 95% Sb utilization, an outstanding coulombic efficiency (CE) of 95% and an impressive lifespan (>110 h). Meanwhile, the Ni 3 Se 2 //Sb/NCCs batteries show great capacity retention of 86.7% after 2000 cycles with an areal capacity of 0.52 mAh cm −2 . Implementation of the designed anode allows for the construction of Sb-based AABs with enhanced rate capability, energy density and cycling performance.