Sodium-ion batteries have received a surge of interests for the alternatives to lithium-ion batteries due to their abundant reserves and low cost. The quest of reliable and high-performance cathode materials is crucial to future Na storage technologies. Herein, poly(3,4-ethylenedioxythiophene) (PEDOT) was successfully introduced to NaV3O8 via in situ oxidation polymerization, which can effectively enhance electron conductivity and ionic diffusion of NaV3O8 material. As a result, these NaV3O8@PEDOT composites exhibit a significantly improved electrochemical performance including cycle stability and rate performance. In particular, NaV3O8@20 wt% PEDOT composite demonstrates better dispersibility and lower charge transfer resistance compared with bare NaV3O8, which delivers the first discharge capacity of 142 mAh·g−1 and holds about 128.7 mAh·g−1 after 300 cycles at a current density of 120 mA·g−1. Even at a high current density of 300 mA·g−1, a high reversible capacity of 99.6 mAh·g−1 is revealed. All these consequences suggest that NaV3O8@20 wt% PEDOT composite may be a promising candidate to serve as a high-rate and long-lifespan cathode material for sodium-ion batteries.

中文翻译：

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NaV3O8/聚（3,4-亚乙基二氧噻吩）复合材料作为可逆钠储存的高倍率和长寿命正极材料

钠离子电池因其储量丰富、成本低廉而成为锂离子电池替代品的热门话题。寻求可靠且高性能的正极材料对于未来的钠储存技术至关重要。在这里，聚（3,4-亚乙基二氧噻吩）（PEDOT）通过原位氧化聚合成功地引入到 NaV3O8 中，可以有效地增强 NaV3O8 材料的电子传导性和离子扩散。因此，这些 NaV3O8@PEDOT 复合材料表现出显着改善的电化学性能，包括循环稳定性和倍率性能。特别是，与裸 NaV3O8 相比，NaV3O8@20 wt% PEDOT 复合材料表现出更好的分散性和更低的电荷转移电阻，其首次放电容量为 142 mAh·g-1 并保持约 128。在 120 mA·g-1 的电流密度下循环 300 次后为 7 mAh·g-1。即使在 300 mA·g-1 的高电流密度下，也显示出 99.6 mAh·g-1 的高可逆容量。所有这些结果表明，NaV3O8@20 wt% PEDOT复合材料可能是作为钠离子电池高倍率和长寿命阴极材料的有希望的候选材料。