Exploring the concept of soft energy unit with improved sustainability and flexibility is critically important for the development of wearable electronics that comes into direct contact with human tissues. Herein, a flexible and self-chargeable sodium-ion full battery was developed by coupling elastic piezo-films with the separator of flexible sodium-ion batteries. This new device achieves excellent flexibility and self-charging performance. It can not only be charged to about 0.65 V under mechanical bending in 150 s or palm patting within 300 s, but also demonstrates interesting self-charging behavior even with quasi-static pressing. In the latter case, the self-charging rate increases with the rising of the applied static forces, which can be ascribed to the sound elasticity of the piezo-film. This work contributes to the development of flexible and self-chargeable electrochemical power devices for soft wearable electronics.