Catalytically enhanced power generation of a self-charging Zn-organic battery without O2-oxidation

Self-charging batteries based on organic cathodes and the oxidation mechanism are intriguing because the exhausted battery can be automatically recharged to resume the electrical energy output. A consensus is that the air or dissolved oxygen in electrolyte are indispensable in the self-charging process, which makes the battery impractical due to external air supply and the electrolyte evaporation from non-sealed batteries. Furthermore, organic cathodes generally exhibit low specific capacities. Here, a new self-charging mechanism is realized by blending Pt/C nanocatalysts with poly(1,5-naphthalenediamine, NAPD) to fabricate cathodes for aqueous Zn-polymer batteries. The discharged cathode can be self-charged to 1.16 V within 8 h while being immersed in electrolyte, without the need for dissolved oxygen. This endows a fully sealed coin cell with self-charging function. Owing to the catalytic activation of primary amino groups in poly(1,5-NAPD), the specific capacity is nearly doubled, reaching a high level of 310 mAh g −1 . The role of nanocatalyst in increasing the self-charging rate and voltage is discussed in detail. To demonstrate practical applications, a battery pack is made by loading thick cathodes and Zn anodes into a 3D-printed six-compartment case. This battery pack can be self-charged to 6.4 V and is used to power a walking robot.