Rational Design of Hybrid Electrolytes for All-Solid-State Lithium Batteries

Rechargeable Li-ion batteries have led to a remarkable revolution in consumer electronics, electric vehicles (EV), and energy storage systems (ESS). Especially, EVs are one of the good options for autonomous vehicles and to reduce CO₂ emissions. Rechargeable Li-ion batteries which have been successfully applied to potable electronics are widely used for EVs. However, shot driving range due to the limited energy density of Li-ion batteries and safety issues should be overcome to meet a requirement for EVs.<br/>Solid polymer electrolytes (SPEs) and hybrid electrolytes with oxide electrolytes are considered promising electrolytes for next-generation all-solid-state lithium batteries because they have much better safety, flexibility, and mechanical stability in the design of the cells, compared with the liquid electrolytes. Current research on solid polymer electrolytes has focused on poly(ethylene oxide)(PEO)-based polymers, but they are restrictively allowed for practical applications because of their weaknesses such as low ionic conductivity at room temperature and poor electrode/electrolyte interface characteristics.<br/>In this presentation, the semi-interpenetrating polymer network PEO-based polymer electrolyte and hybrid electrolytes with oxide electrolytes were used to investigate the performance of Li-polymer batteries by using Ni-rich NMC such as LiNi_0.8Mn_0.1Co_0.1O₂ (NMC811) as cathode materials and carbon-silicon composite or lithium metal as anode materials. All-solid-state batteries are successfully operated at room temperature and 45^oC with high rate capability and enhanced cycle performances.