Polyethylene oxide (PEO)-based solid polymer electrolyte (SPE) is considered to have great application prospects in all-solid-state li-ion batteries. However, the application of PEO-based SPEs is hindered by the relatively low ionic conductivity, which strongly depends on its crystallinity and density of grain boundaries. In this work, a simple and effective press-rolling method is applied to reduce the crystallinity of PEO-based SPEs for the first time. With the rolled PEO-based SPE, the LiFePO₄/SPE/Li all-solid li-ion battery delivers a superior rechargeable specific capacity of 162.6 mAh g⁻¹ with a discharge-charge voltage gap of 60 mV at a current density of 0.2 C with a much lower capacity decay rate. The improvement of electrochemical properties can be attributed to the press-rolling method, leading to a doubling conductivity and reduced activation energy compared with that of electrolyte prepared by traditional cast method. The present work provides an effective and easy-to-use grain reforming method for SPE, worthy of future application.

聚环氧乙烷（PEO）基固体聚合物电解质（SPE）被认为在全固态锂离子电池中具有广阔的应用前景。但是，基于PEO的SPE的应用受到相对较低的离子电导率的阻碍，而离子电导率很大程度上取决于其结晶度和晶界密度。在这项工作中，首次应用了一种简单有效的压延方法来降低基于PEO的SPE的结晶度。借助轧制的基于PEO的SPE，LiFePO ₄ / SPE / Li全固态锂离子电池可在电流密度为0.2时提供162.6 mAh g ^-1的出色可充电比容量和60 mV的充放电电压间隙C容量衰减率低得多。电化学性能的提高可归因于压延法，与传统浇铸法制备的电解质相比，电导率提高了一倍，活化能降低。目前的工作为固相萃取提供了一种有效且易于使用的晶粒重整方法，值得将来应用。