Polyetherimide (PEI) for high-temperature energy storage still face the critical problem of low discharged energy density. The dramatic increase in leakage current is the basic reason for the deterioration of energy storage characteristics under elevated temperatures. Herein, a molecular engineering strategy is presented to suppress electrical conduction by introducing a high electron-affinity dianhydride structure into the main chain of PEI. The energy band structure of PEI is markedly affected by the dianhydride, which is illustrated by experimental research and density functional theory (DFT) calculations. Structures with high electron-affinity act as trap centers to capture carriers, significantly inhibiting conduction at elevated temperatures. Consequently, the PEI hybrid film exhibits a discharged energy density of 4.01 J/cm³ and a charge-discharge efficiency of 91% at 150 °C. The high throughput and easy processing of the PEI hybrid film makes it a potential choice for energy storage under harsh conditions. This work represents a route for preparing polymer dielectrics with outstanding energy storage characteristics capable of operating in high temperature environments.

用于高温储能的聚醚酰亚胺（PEI）仍然面临放电能量密度低的关键问题。漏电流的急剧增加是高温下储能特性恶化的根本原因。在此，提出了一种分子工程策略，通过在 PEI 主链中引入高电子亲和力的二酐结构来抑制导电。能量PEI 的能带结构明显受到二酐的影响，实验研究和密度泛函理论 (DFT) 计算表明了这一点。具有高电子亲和力的结构充当捕获载流子的陷阱中心，显着抑制高温下的传导。因此，PEI杂化薄膜在150℃下表现出4.01 J/cm ^{3的放电能量密度}和91%的充放电效率。PEI混合薄膜的高通量和易加工性使其成为恶劣条件下储能的潜在选择。这项工作代表了一种制备具有出色的储能特性、能够在高温环境下工作的聚合物电介质的路线。