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Abstract：
Garnet-type oxide Li6.4 La3 Zr1.4 Ta0.6 O12 (LLZTO) features superior ionic conductivity and good stability toward lithium (Li) metal, but requires high-temperature sintering (≈1200 °C) that induces high fabrication cost, poor mechanical processability, and high interface resistance. Here, a novel high-performance tricomponent composite solid electrolyte (CSE) comprising LLZTO-4LiBH4 /xLi3 BN2 H8 is reported, which is prepared by ball milling the LLZTO-4LiBH4 mixture followed by hand milling with Li3 BN2 H8 . Green pellets fabricated by heating the cold-pressed CSE powders at 120 °C offer ultrafast room-temperature ionic conductivity (≈1.73 × 10-3 S cm-1 at 30 °C) and ultrahigh Li-ion transference number (≈0.9999), which enable the Li|Li symmetrical cells to cycle over 1600 h at 30 °C with only 30 mV of overpotential. Moreover, the Li|CSE|TiS2 full cells deliver 201 mAh g-1 of capacity with long cyclability. These outstanding performances are due to the low open porosity in the electrolyte pellets as well as the high intrinsic ionic conductivity and easy deformability of Li3 BN2 H8 .
摘要：
石榴石型氧化物Li6.4La3Zr1.4Ta0.6O12（LLZTO）具有优异的离子导电性和对锂（Li）金属的良好稳定性，但是需要高温烧结（约1200°C），这会导致高制造成本，机械加工性差，和高界面电阻。这里,报道了一种包含LLZTO-4LiBH4/xLi3BN2H8的新型高性能三组分复合固体电解质（CSE），它是通过球磨LLZTO-4LiBH4混合物，然后用Li3BN2H8手工研磨制备的。通过在120°C下加热冷压CSE粉末制成的绿色颗粒可提供超快的室温离子电导率（在30°C下约为1.73×10-3Scm-1）和超高的锂离子迁移数（约0.9999），这使得Li|Li对称电池在30°C下以仅30mV的过电位循环超过1600h。此外，Li|CSE|TiS2全电池提供201mAhg-1的容量，具有长循环能力。这些出色的性能是由于电解质颗粒中的低开孔率以及Li3BN2H8的高固有离子电导率和易变形性。
