Flexible fiber-shaped Li-CO₂ batteries are regarded to be a potential candidate to power accessories for wearable electronics due to their high theoretical energy density and carbon-neutral capability. However, the difficulties of electrode preparation and architecture design make it challenging for current Li-CO₂ batteries to keep a suitable balance between electrochemical performance and multifunctionality, one-dimensional configuration and so forth. Herein, a flexible, stretchable, water-/fire-proof fiber-shaped Li-CO₂ battery is constructed through an integrated electrode design strategy and a mechanical engineering-inspired “spring”-like device architecture. Impressively, the as-prepared highly-active Mo₂N anchored N-doped carbon nanotubes/carbon fiber hybrid bundle (CFB@NCNT-Mo₂N) cathode delivers a large full capacity of 5586.0 µAh cm⁻¹, corresponding to a high energy density of 14 250 $\text{Wh}{\text{kg}}_{\text{cathode}}^{-1}$. Meanwhile, it also demonstrates a low charge potential of ≈3.7 V, excellent rate capabilities, and outstanding long-term cycling stability of 525 cycles. Furthermore, the constructed “spring”-like fiber-shaped Li-CO₂ battery device using CFB@NCNT-Mo₂N and a newly-proposed gracile fibrous Li metal anode exhibits excellent adaptability to deformations including bending and stretching, as well as other favorable features like water-/fire-resistance. The successful demonstration of the proposed high-performance and multifunctional Li-CO₂ batteries provide an effective model for designing future flexible energy storage devices beyond metal-gas batteries for wearables in specific application scenarios.

中文翻译：

---

具有高能量密度的柔性、可拉伸、防水/防火纤维状 Li-CO2 电池

柔性纤维状 Li-CO ₂电池由于具有高理论能量密度和碳中和能力，被认为是为可穿戴电子产品配件供电的潜在候选者。然而，电极制备和结构设计的困难使得目前的Li-CO ₂电池难以在电化学性能和多功能性、一维构型等方面保持适当的平衡。在此，一种柔性、可拉伸、防水/防火的纤维状 Li-CO ₂电池是通过集成电极设计策略和受机械工程启发的“弹簧”状设备架构构建的。令人印象深刻的是，所制备的高活性 Mo ₂N 锚定 N 掺杂碳纳米管/碳纤维混合束 (CFB@NCNT-Mo ₂ N) 阴极提供 5586.0 µAh cm ^-1的大满容量，对应于 14 250 的高能量密度$\text{瓦}{\text{公斤}}_{\text{阴极}}^{-\mathrm{1个}}$. 同时，它还表现出≈3.7 V的低充电电位、出色的倍率性能和出色的525次循环的长期循环稳定性。此外，使用CFB@NCNT-Mo ₂ N和新提出的纤细纤维锂金属负极构建的“弹簧”状纤维状Li-CO ₂电池装置对包括弯曲和拉伸在内的变形以及其他变形具有出色的适应性。防水/防火等有利特性。所提出的高性能和多功能 Li-CO ₂电池的成功演示为在特定应用场景中设计超越金属气体电池的可穿戴设备的未来柔性储能设备提供了有效模型。