Addressing the interface issues of all-solid-state lithium batteries by ultra-thin composite solid-state electrolyte combined with the integrated preparation technology

The interfacial engineering in solid-state lithium batteries (SSLBs) is attracting escalating attention due to the profoundly enhanced safety, energy density, and charging capabilities of future power storage technologies. Nonetheless, polymer/ceramic interphase compatibility, serious agglomeration of ceramic particles, and discontinuous ionic conduction at the electrode/electrolyte interface seriously limit Li+ transport in SSLBs and block the application and large-scale manufacturing. Hence, garnet Li7La3Zr2O12 (LLZO) nanoparticles are introduced into the polyacrylonitrile (PAN) nanofiber to fabricate a polymer-ceramic nanofiber-enhanced ultrathin SSE membrane (3D LLZO-PAN), harnessing nanofiber confinement to aggregate LLZO nanoparticles to build the continuous conduction pathway of Li+. In addition, a novel integrated electrospinning process is deliberately designed to construct tight physical contact between positive electrode/electrolyte interphases. Importantly, the synergistic effect of the PAN, polyethylene oxide (PEO), and lithium bis((trifluoromethyl)sulfonyl)azanide (LiTFSI) benefits a stable solid electrolyte interphase (SEI) layer, resulting in superior cycling performance, achieving a remarkable 1500 h cycling at 0.2 mA cm-2 in the Li|3D LLZO-PAN|Li battery. Consequently, the integrated polymer-ceramic nanofiber-enhanced SSEs simultaneously achieve the balance in ultrathin thickness (16 mu m), fast ion transport (2.9 x 10-4 S cm-1), and superior excellent interface contact (15.6 Omega). The LiNi0.8Co0.1Mn0.1O2|3D LLZO-PAN|Li batteries (2.7-4.3 V) can work over 200 cycles at 0.5 C. The pouch cells with practical LiNi0.8Co0.1Mn0.1O2||Li configuration achieve an ultrahigh energy density of 345.8 Wh kg-1 and safety performance. This work provides new strategies for the manufacturing and utilization of high-energy-density SSLBs.image