CNT-Intertwined Polymer Electrode toward the Practical Application of Wearable Devices.

One of the greatest challenges for wearable electronics is the lack of virtually flexible electrodes with satisfactory electrochemical performance, and there is always a "softness vs effective capacity" dilemma. Herein, a polymer electrode is proposed. The carefully chosen and partially conjugated polyimide realizes the dual function of a flexible agent and an active agent. The softness of the electrode is rendered by the polymer, while the carbon nanotube ensures electron transfer (ET) within the polymer. A modified electrospinning method has been used in the preparation of a carbon nanotube (CNT)-intertwined polyimide (PI) film. The binder-free and current collector-free polymer electrode has as high as 80% active phase and releases near-theoretical capacity accompanied by very stable cycling up to 200 cycles. Owing to the dual role of the polymer component, the softness vs effective capacity dilemma has been well addressed. Aiming at the practical application, a fatigue test has been first conducted in a practical mode and the well-reserved electrochemical activity under extreme stress change as well as in plenty of electrolyte has been revealed. The work realizes that the flexible electrode well fulfills the requirement and sheds more light on the application of the polymer electrode materials.