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

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 m Ah 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 m Ah cm^(-2).Implementation of the designed anode allows for the construction of Sb-based AABs with enhanced rate capability,energy density and cycling performance.

Loosely coordinating diluted highly concentrated electrolyte toward -60℃ Li metal batteries

Lithium metal batteries(LMBs) promise energy density over 400 Wh kg^(-1).However,they suffer severe electrochemical performance deterioration at sub-zero temperatures.Such failure behavior highly correlates to inferior lithium metal anode(LMA) compatibility and sluggish Li^(+) desolvation.Here,we demonstrate that cyclopentylmethyl ether(CPME) based diluted high-concentration electrolyte(DHCE)enables-60℃ LMBs operation.By leveraging the loose coordination between Li^(+) and CPME,such developed electrolyte boosts the formation of ion clusters to derive anion-dominant interfacial chemistry for enhancing LMA compatibility and greatly accelerates Li^(+) desolvation kinetics.The resulting electrolyte demonstrates high Coulombic efficiencies(CE),providing over 99.5%,99.1%,98.5% and 95% at 25,-20,-40,and-60℃respectively.The assembled Li-S battery exhibits remarkable cyclic stability in-20,and-40℃ at 0.2 C charging and 0.5 C discharging.Even at-60℃,Li-S cell with this designed electrolyte retains> 70% of the initial capacity over 170 cycles.Besides,lithium metal coin cell and pouch cell with10 mg cm^(-2) high S cathode loading exhibit cycling stability at-20℃.This work offers an opportunity for rational designing electrolytes toward low temperature LMBs.