Flexible electronics are being pursued as replacements for rigid consumer electronic products such as smartphones and tablets, as well as for wearable electronics, implantable medical devices, and RFIDs. Such devices require flexible batteries with electrodes that maintain their electro-chemical performance during multiple bending cycles. These electrodes typically consist of an active battery material blend with a conductive additive and a binder. Whilst the choice of active battery material is typically dictated by the desired battery power and energy requirements, there is more freedom in changing the conductive additives to cope with strain induced during the bending of flexible batteries. Here we compare the mechanical and electrical properties of free standing cathodes using lithium cobalt oxide (LiCoO₂) as the active material and 10–20 wt% of amorphous carbon powder (CP) or carbon nanotubes (CNTs) as conductive additives. We found that the CNT based electrodes showed less crack formation during bending and have a Young's modulus up to 30 times higher than CP electrodes (10 wt% loading). Further, the electrical resistance of pristine CNT electrodes is 10 times lower than CP electrodes (20 wt% loading). This difference further increases to a 28 times lower resistance for CNT films after 2000 bending cycles. These superior properties of CNT films are reflected in the electrochemical tests, which show that after bending, only the electrodes with 20 wt% of CNTs remain operational. This study therefore highlights the importance of the conductive additives for developing reliable flexible batteries.

柔性电子正在寻求替代刚性消费电子产品（例如智能手机和平板电脑）以及可穿戴电子产品，植入式医疗设备和RFID的替代产品。这样的设备需要具有电极的柔性电池，该电极在多个弯曲循环中保持其电化学性能。这些电极通常由活性电池材料与导电添加剂和粘合剂的混合物组成。尽管活性电池材料的选择通常由所需的电池功率和能量要求决定，但在改变导电添加剂以应对在柔性电池弯曲过程中产生的应变方面，存在更大的自由度。在这里，我们比较了使用钴酸锂（LiCoO ₂）作为活性材料，并使用10-20 wt％的无定形碳粉（CP）或碳纳米管（CNT）作为导电添加剂。我们发现，基于CNT的电极在弯曲过程中显示出较少的裂纹形成，并且其杨氏模量比CP电极高出30倍（10 wt％负载）。此外，原始CNT电极的电阻比CP电极低20倍（20 wt％的负载）。在经过2000次弯曲循环后，此差异进一步增加，使CNT膜的电阻降低了28倍。碳纳米管薄膜的这些优越性能在电化学测试中得到了反映，该实验表明，弯曲后，只有碳纳米管含量为20 wt％的电极才能正常工作。因此，这项研究强调了导电添加剂对开发可靠的柔性电池的重要性。