Abstract SnO2 as a promising anode material possesses a high theoretical capacity and a safe lithiation potential; however, it suffers from low cycle stability and poor rate capability due to its nano-aggregation effect, structural instability, and sluggish electrode kinetics. Herein a one-pot hydrothermal process was developed to craft ultrasmall SnO2 nanocrystals uniformly encapsulated in the polyimide matrix through a facile in-situ polymerization. The polyimide phase can suppress the over growth of SnO2 nanoparticles while preventing from their re-aggregation through the space-confined effect during the material synthesis. The robust polyimide matrix can be also served as a protective layer to relieve the volume change of SnO2 nanoparticles and inhibit the cracks propagation throughout the whole electrode during the charge/discharge processes. Moreover, the carbonyl-contained polyimide is intrinsically redox-active, capable of affording acceptable ionic conduction ability. Remarkably, the as-fabricated SnO2@PI composite anode exhibits a reversible capacity as high as 897 mAh g−1 at 0.1 A g−1 and a high rate capability (479 mAh g−1 at 2.0 A g−1) with a higher retention (53%) than pure SnO2 (39%). The SnO2@PI anode also retains a capacity of 653 mAh g−1 at 0.5 A g−1 after 150 cycles. This work would offer an alternative strategy by incorporating metal oxide nanoparticles into the redox-active polymer matrix for advanced anode materials with high rate capability and long-term cyclability.

中文翻译：

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将超小 SnO2 纳米晶体原位限制在氧化还原活性聚酰亚胺中，用于高倍率和长循环负极材料

摘要 SnO2 作为一种很有前途的负极材料，具有较高的理论容量和安全的锂化电位；然而，由于其纳米聚集效应、结构不稳定性和缓慢的电极动力学，它具有低循环稳定性和较差的倍率性能。本文开发了一种一锅式水热工艺，通过简单的原位聚合制备均匀封装在聚酰亚胺基质中的超小 SnO2 纳米晶体。聚酰亚胺相可以抑制 SnO2 纳米粒子的过度生长，同时防止它们在材料合成过程中通过空间限制效应重新聚集。坚固的聚酰亚胺基体还可以作为保护层，以减轻 SnO2 纳米粒子的体积变化，并在充电/放电过程中抑制裂纹在整个电极中的传播。此外，含羰基的聚酰亚胺本质上具有氧化还原活性，能够提供可接受的离子传导能力。值得注意的是，制造的 SnO2@PI 复合负极在 0.1 A g-1 时具有高达 897 mAh g-1 的可逆容量和高倍率性能（在 2.0 A g-1 时为 479 mAh g-1），具有更高的保留 (53%) 比纯 SnO2 (39%)。SnO2@PI 阳极在 0.5 A g-1 循环 150 次后仍保持 653 mAh g-1 的容量。这项工作将通过将金属氧化物纳米粒子掺入氧化还原活性聚合物基质中来提供一种替代策略，用于具有高倍率能力和长期循环能力的先进负极材料。制造的 SnO2@PI 复合负极在 0.1 A g-1 时表现出高达 897 mAh g-1 的可逆容量和高倍率性能（2.0 A g-1 时为 479 mAh g-1），具有更高的保留率（ 53%) 比纯 SnO2 (39%)。SnO2@PI 阳极在 0.5 A g-1 循环 150 次后仍保持 653 mAh g-1 的容量。这项工作将通过将金属氧化物纳米粒子掺入氧化还原活性聚合物基质中来提供一种替代策略，用于具有高倍率能力和长期循环能力的先进负极材料。制造的 SnO2@PI 复合负极在 0.1 A g-1 时表现出高达 897 mAh g-1 的可逆容量和高倍率性能（2.0 A g-1 时为 479 mAh g-1），具有更高的保留率（ 53%) 比纯 SnO2 (39%)。SnO2@PI 阳极在 0.5 A g-1 循环 150 次后仍保持 653 mAh g-1 的容量。这项工作将通过将金属氧化物纳米粒子掺入氧化还原活性聚合物基质中来提供一种替代策略，用于具有高倍率能力和长期循环能力的先进负极材料。