An ultrafast rechargeable and high durability lithium metal battery using composite electrolyte with the three-dimensional inorganic framework by Li6.4La3Zr1.4Ta0.6O12 surface functionalization

Abstract

The liquid electrolyte used in traditional lithium-ion batteries has risks of leakage, combustion and explosion. Solid electrolyte is one of the effective strategies to solve the safety problems of lithium-ion batteries. And the use of solid electrolytes makes it possible to use lithium metal as an anode to achieve higher energy densities. At present, the main factors restricting the performance improvement of all-solid-state lithium batteries are the low electrochemical performance of electrolytes and poor solid-solid interface contact. The composite electrolyte has the advantages of both inorganic materials and polymers, but its electrochemical performance is still not up to the requirements of use. In situ synthesis of LaRuO3 with perovskite structure on the surface of Li6.4La3Zr1.4Ta0.6O12(LLZTO) induces the formation of Li2Zr2O7 while introducing defects. The Li2Zr2O7 phase "welds" inorganic particles into three-dimensional(3D) inorganic framework, increasing the reaction sites between inorganic fillers and polymers. Compared with the primitive sample, the ionic conductivity of the modified electrolyte is increased by an order of magnitude at room temperature, wherein the lithium-ion conductivity of the composite electrolyte with 3% LaRuO3 is as high as 6.06 × 10−4 S cm−1. At 5C, the discharge specific capacity of LiFePO4 | [email protected] 3% LRO | Li can reach 114.6 mAh g−1; After 400 cycles, the discharge specific capacity remains at 129.6 mAh g−1. Under the same conditions, the discharge specific capacities of the unmodified samples are only 92.4 mAh g−1 and 35 mAh g−1. The high rate discharge performance of solid-state lithium metal battery supports the high torque output of motor, which improves the acceleration performance of electric vehicles or ships. The high capacity and excellent cycle performance of solid-state lithium metal battery can significantly extend the driving range and service life of electric vehicles.