Search

The garnet-type solid Li-ion conductor, Li6.4La3Zr1.4Ta0.6O12, is viewed as a promising solid-state electrolyte for the next-generation high-performance Li-ion battery because of its high ionic conductivity and stability. The previous researches, in order to avoid Li volatilization loss during solid-state reaction of sintering, mother powder with the same composition as green bodies was usually used to cover the samples, it would waste the expensive raw materials and increase the fabrication cost. In this study, a new method was proposed to prepare the Li6.4La3Zr1.4Ta0.6O12 ceramic solid-state electrolyte where the Li loss is compensated by the outside Li2CO3. Samples prepared by this method have pure garnet phase and compact micromorphology with few pores. These samples have a high Li-ion conductivity of 2.9×10−4 S/cm and a low activation energy of 0.37 eV at room temperature. The electronic conductivity is 1.08×10−8 S/cm, which can be neglected for solid-state electrolyte. [ABSTRACT FROM AUTHOR]

Cubic perovskite–type oxide Li 3/8 Sr 7/16 Hf 1/4 Ta 3/4 O 3 (LSHT) is a promising solid electrolyte material for next–generation Li–ion batteries such as all–solid–state Li batteries and Li–redox flow batteries due to its high room–temperature Li–ion conductivity and good chemical compatibility with commercial organic liquid electrolyte. High relative density is another important requirement for these applications. Here we investigate the influence of sintering additives (Li 3 BO 3 , Li 4 SiO 4 , LiF) on the density, the total Li–ion conductivity, the interfacial conductivity against commercial liquid electrolyte, and the cycling performance of the hybrid Li-ion cells. The results show that comparing with other additives, LSHT sintered with 2 wt% LiF shows the highest Li–ion conductivity (3.3 × 10 −4 S cm −1 ) and the smallest interfacial resistance (125 Ω cm 2 ) against organic electrolyte at room temperature; Li/LiFePO 4 batteries with LSHT pellets fired with 2 wt% LiF have the best cyclability and the highest coulombic efficiency (99.6 ± 0.04%) in 50 cycles. [ABSTRACT FROM AUTHOR]