RESUMEN
The VB2-air battery is currently known for its highest theoretical specific capacity, up to 4060 mA h g-1. This together with the excellent environmental compatibility and high security endues with promising application prospects for the battery. However, the self-discharge of the anode caused by hydrogen evolution corrosion results in a severe capacity loss during discharge. In this work, we studied the FeNi-LDH intercalation for suppressing the self-discharge of the VB2-air battery. We adopt the vertical FeNi-LDH arrays to modify VB2 particles. Hydroxyl ions participating in the discharge reaction are transported along adsorbed water molecules and hydroxide host layers through a rapid hydrogen bond formation and cleavage to the VB2 surface, while the depolarizer hydrogen ions are isolated. The hydrogen evolution corrosion on the VB2 anode is effectively suppressed. As a result, the discharge specific capacity of the battery is increased by 700 mA h g-1.
RESUMEN
Garnet-type solid-state electrolytes (SSEs) show a promising application in solid-state Li batteries. Poor interfacial contact with lithium causing large interfacial impedance and dendrite penetration is a problem. Inspired by unique H+/Li+ exchange of garnet electrolyte, we used an AgNO3 aqueous solution induced strategy to construct a lithiophilic layer in situ on the garnet surface without any specific apparatus. Experimental analysis reveals the uniform distribution of Ag nanoparticles and significantly enhanced affinity between the solid state electrolyte (SSE) and Li anode for the Li-Ag alloying. As expected, the interfacial area specific resistance (ASR) is greatly reduced to â¼4.5 Ω cm2, accompanying with long-cycling stability for â¼3500 h at 0.2 mA cm-2 and high critical current density of 0.75 mA cm-2. With modified SSEs, quasi-solid-state batteries with a LiFePO4 or LiNi0.5Co0.2Mn0.3O2 cathode operate well at room temperature and an all-solid-state LiFePO4/garnet/Li battery displays good cycling stability for over 200 cycles at 60 °C.
RESUMEN
A facile and effective method to modify Li anode for Li-S cells by exposing Li foils to tetrahydrofuran (THF) solvent, oxygen atmosphere and trimethylsilyl chloride ((CH3)3SiCl) liquid in sequence is proposed. The results of SEM and XPS show the formation of a homogeneous and dense film with a thickness of 84 nm on Li metal surface. AC impedance and polarization test results show the improved interfacial stability. The interfacial resistances as well as polarization potential difference have obviously decreased as compared with that of a pristine Li anode. CV and charge-discharge test results demonstrate that more reversible discharge capacity and higher Coulombic efficiency can be achieved. Specific capacity of 760 mAh g(-1) and an average Coulombic efficiency of 98% are retained after 100 cycles at 0.5C without LiNO3 additive. Additionally, the Li-S cell with a modified Li anode displays a greatly improved rate performance with â¼425 mAh g(-1) at 5C, making it more attractive and competitive in the applications of high-power supply.