On the contrary, rechargeable batteries are still indispensable in portable electronics, considering the discontinuity of the energy source (ie, solar, thermal, wind, and mechanical energy) of most energy harvesters. In order to improve the flexibility of batteries, it is essential to substitute the rigid package and current collector of commercial batteries with bendable or stretchable counterparts.[1, 13] Recent research has reported paper or textile batteries with the utilization of graphene,[14] carbon nanotubes (CNT),[15] or carbon nanofiber cloth [16] as the flexible substrate, whereas the scale-up difficulty and high cost of these materials impede their practical commercialization. Herein, we designed a wearable power unit by integrating a whole-textile TENG-cloth and a flexible lithium-ion battery (LIB) belt. Common flexible but insulating polyester fabrics were transformed into conductive with an electroless plating of a conformal Ni film, which were then utilized both as electrodes in the TENG-cloth and as current collectors in the LIB belt. The TENG-cloth demonstrated the capability of converting the mechanical energy of various human motions into electricity when being worn at different positions on the human body; the LIB belt showed decent electrochemical performances even being severely folded at 180 for 30 times. Furthermore, the LIB belt was charged by the TENG-cloth for 3 cycles, and powered a heartbeat meter strap capable of remote communication with a smart phone, verifying the viability of the wholewearable and self-charging power unit for future wearable smart electronics.

As the conductive electrode is one of the key components in a TENG, it is crucial to develop a soft and wearable conductor for wearable TENG. Common soft polyester fabric was selected as the starting substrate, and was consecutively coated with conductive Ni film (Ni-cloth) and insulating parylene film (parylene-cloth), as schematically illustrated in Figure 1a. Due to the difficulty in handling individual polyester microwire, belt-type Ni-cloth, and parylene-cloth (5-mm wide) were used as the building block (see Figure 1 a, b), and finally woven into a 5 cm× 5 cm TENG-cloth (see Figure 1 a, c). All the Ni-cloth belts were connected together as one electrode of the TENG, while all the parylene-cloth belts were connected as the other. After the Ni-coating, white polyester cloth changes into silver; while parylene layer is relatively transparent (see Figure 1 b). The woven