A self-healing aqueous ammonium-ion micro batteries based on PVA-NH₄Cl hydrogel electrolyte and MXene-integrated perylene anode

The successful study of self-healing aqueous micro batteries (AMBs) which inherit the advantages of aqueous batteries and have the ability to automatically repair damage is of great significance for the development of smart wearable and portable electronic devices. However, the rate performance and the related power density of developed self-healing AMBs using metal ions as charge carriers is limited, due to the strong interaction between metal ions and electrode materials. Therefore, there is great potential for developing self-healing NH₄⁺ AMBs, because of the outstanding advantages of NH₄⁺ such as extremely abundant reserves, smaller hydrated ion radius and little molar mass. However, the development of self-healing NH₄⁺ AMBs is still an extremely challenge due to the difficulty in developing self-healing hydrogels and instability of anode materials. Even though, the firstly self-healing NH₄⁺ AMBs based on tailoring hydrogel electrolyte and MXene-integrated perylene anode were successfully assembled. As expected, self-healing NH₄⁺ AMBs exhibit excellent energy density (82.48 µWh·cm⁻²) and power density (3.09 mW·cm⁻²), cycle life (81.67% after 3000 GCD cycles), flexibility (95.68% under 180°) and self-healing ability (94.16% after the 10^th self-healing cycles).