A carbon nanotubes/graphene composite is grown on nickel foil without additional catalysts by one-step ambient pressure chemical vapor deposition (CVD). Next, the carbon nanotubes/graphene composite is modified by radio frequency (RF) nitrogen plasma. Finally, to improve its initial coulombic efficiency/electrochemical stability, lower potential during the charge process (coin cell), and boost potential during the discharge process (lithium-ion battery), alumina is deposited onto the N-doped carbon nanotubes/graphene composite by RF magnetron sputtering at different power levels and periods of time. The charge specific capacity (597 mAh/g) and initial coulombic efficiency (81.44% > 75.02% for N-doped carbon nanotubes/graphene) of Al₂O₃/N-doped CNTs/graphene for the coin cell reached a maximum at the best sputtering condition ( and ). Al₂O₃/N-doped CNTs/graphene (the best sputtering condition) exhibits higher initial coulombic efficiency (79.8%) compared with N-doped CNTs/graphene (initial coulombic efficiency: 74.3%) for the lithium-ion battery. Furthermore, the achievement fraction (about 70%) of full charge capacity (coin cell) for Al₂O₃/N-doped carbon nanotubes/graphene (the best sputtering condition) is higher than that (about 30%) for N-doped carbon nanotubes/graphene at a voltage lower than about 0.25 V. Moreover, it also shows a little higher electrochemical stability (coin cell) of charge capacity for Al₂O₃/N-doped carbon nanotubes/graphene (the best sputtering condition) in comparison with N-doped carbon nanotubes/graphene and Al₂O₃/N-doped CNTs/graphene (the best sputtering condition) exhibits better cyclic stability (lithium-ion battery) of discharge capacity compared with N-doped CNTs/graphene.

中文翻译：

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氧化铝膜对N掺杂碳纳米管/石墨烯复合材料作为锂离子电池负极材料的影响

通过一步式环境压力化学气相沉积（CVD），无需额外的催化剂即可在镍箔上生长碳纳米管/石墨烯复合材料。接下来，通过射频（RF）氮等离子体对碳纳米管/石墨烯复合材料进行改性。最后，为了提高其初始库伦效率/电化学稳定性，在充电过程中降低电势（纽扣电池）并在放电过程中提高电势（锂离子电池），将氧化铝沉积在N掺杂的碳纳米管/石墨烯复合材料上通过射频磁控溅射在不同的功率水平和时间段。Al ₂ O ₃的电荷比容量（597 mAh / g）和初始库伦效率（对于N掺杂的碳纳米管/石墨烯而言，为81.44％> 75.02％）在最佳溅射条件下，纽扣电池的/ N掺杂CNT /石墨烯达到最大值（ 和 ）。与锂离子电池的N掺杂CNT /石墨烯（初始库仑效率：74.3％）相比，Al ₂ O ₃ / N掺杂CNT /石墨烯（最佳溅射条件）表现出更高的初始库伦效率（79.8％）。此外，Al ₂ O ₃ / N掺杂的碳纳米管/石墨烯（最佳溅射条件）的完全充电容量（纽扣电池）的达到率（约70％）高于N掺杂的（约30％）。碳纳米管/石墨烯的电压低于约0.25V。此外，它对Al ₂ O ₃的充电容量还显示出更高的电化学稳定性（纽扣电池）/ N掺杂的碳纳米管/石墨烯（最佳溅射条件）与N掺杂的碳纳米管/石墨烯和Al ₂ O ₃ / N掺杂的CNTs /石墨烯（最佳溅射条件）相比，具有更好的循环稳定性（锂离子）电池）的放电容量与N掺杂的CNT /石墨烯相比。