Biomass dielectric polymers hold promise in developing renewable and biodegradable capacitive energy storage devices. However, their typical discharged energy density remains relatively low (<20 J/cm³) compared to other existing synthetic polymers derived from petroleum sources. Here a greatly enhanced discharged energy density is reported in diluted cyanoethyl cellulose (CEC) nanocomposites with inclusion of ultralow loadings (0.3%, in volume) of 30-nm-sized TiO₂ nanoparticles. Owing to the interfacial polarization introduced by interface, the composite of 0.3% exhibits a large dielectric constant of 29.2 at 1 kHz, which can be described by interphase dielectric model. Meanwhile, the introduction of nanofillers facilitate the formation of deeper traps impeding electrical conduction in CEC, which results in an ultrahigh breakdown strength of 732 MV/m. As a result, a remarkable discharged energy density of 12.7 J/cm³ with a charge-discharge efficiency above 90% is achieved, exceeding current ferroelectric-based and biomass-based nanocomposites. Our work opens a novel route for scalable biomass-based dielectrics with high energy storage properties.

中文翻译：

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在生物质基纳米复合材料中具有极高的能量密度，纳米填料的超低负载


生物质介电聚合物在开发可再生和可生物降解的电容式储能器件方面前景广阔。然而，与来自石油来源的其他现有合成聚合物相比，它们的典型放电能量密度仍然相对较低 （<20 J/cm³）。据报道，在稀释的氰乙基纤维素 （CEC） 纳米复合材料中，含有超低负载量（体积为 0.3%）的 30 nm 尺寸 TiO₂ 纳米颗粒，放电能量密度大大提高。由于界面引入的界面极化，0.3% 的复合材料在 1 kHz 时表现出 29.2 的大介电常数，这可以用相间介电模型来描述。同时，纳米填料的引入有助于在 CEC 中形成阻碍导电的更深陷阱，从而产生 732 MV/m 的超高击穿强度。结果，实现了 12.7 J/cm³ 的显着放电能量密度，充放电效率超过 90%，超过了目前的铁电基和生物质基纳米复合材料。我们的工作为具有高储能特性的可扩展生物质基电介质开辟了一条新途径。