Solid-state lithium batteries using composite polymer electrolytes (CPEs) have attracted much attention owing to their higher safety compared to liquid electrolytes and flexibility compared to ceramic electrolytes. However, their unsatisfactory lithium-ion conductivity still limits their development. Herein, a high ion conductive CPE with multiple continuous lithium pathways is designed. This new electrolyte consists of poly(vinylidene fluorideco-hexafluoropropylene) (PVDF-HFP) and lithiated X type zeolite (Li-X), which possesses a high ionic conductivity (1.98 × 10⁻⁴ S/cm), high lithium transference number (t ${}_{{\mathrm{L}\mathrm{i}}^{+}}$ = 0.55), wide electrochemical window (4.7 V), and excellent stability against the lithium anode. Density functional theory (DFT) calculation confirms that the Lewis acid sites in zeolite can graft with N,N-dimethylformamide (DMF) and PVDF-HFP chains, resulting in decreased crystallinity of polymer and providing rapid Li⁺ transmission channels. When used in a full cell, the solid Li|Li-X-3%|LiFePO₄ cell displays excellent cycling stability and rate performance at room temperature and 60 °C. Furthermore, pouch cells with the Li-X-3% electrolyte exhibit brilliant safety under extreme conditions, such as folding and cutting. Thus, this proposed zeolite-PVDF-HFP CPE represents a promising potential in the application of making a safer, higher performing, and flexible solid-state lithium battery.

Despite the high energy density of lithium-rich (Li-rich) cathodes, their implementation is hampered by the unsatisfied rate capacity and poor cycling performance accompanied with substantial voltage decay. To address these issues, the hierarchical yolk-shell structured Li_1.2Mn_0.54Ni_0.13Co_0.13O₂ cathodes (YK-LMNCO) was proposed and synthesized through a facile glycerol assisted solvothermal approach and the following lithiation process. Benefitting from the shortened lithium diffusion lengths and the enhanced tolerance to the large volume variation upon lithium ions intercalation/de-intercalation, the unique structure reciprocates an initial coulombic efficiency of 85.8%, an outstanding capacity retention rate of 89.1% after cycling at 2.0 C for 200 cycles with a minor voltage drop, and a capacity retention rate of 93.8% after cycling at 10.0 C for 500 cycles, 85.2% for 1,000 cycles. When assembled with graphite as anode, the YK-LMNCO//graphite full cell shows a remarkable capacity retention rate of 87.2% after cycling at 5.0 C for 50 cycles. Our facile strategy for constructing the yolk-shell structured Li-rich cathodes with high capacity and voltage stability sheds light on synthesizing other lithium storage materials.