Green fruit organic primary battery: Positive citric acid, negative sodium tert-pentoxide

[Display omitted] •New electrochemical system of primary battery.•Both the positive and negative electrodes are organic molecules.•Primary battery without metal electrode.•The waste of primary battery is easy to deal with.•Primary battery without transition metal oxide. For the lack of new chemical system, the primary battery can only use metal as negative materials and transition metal oxide as positive materials, resulting in mineral resources and environmental problems. Here, we reported an organic primary battery. The negative electrode was sodium tert-pentoxide and the positive electrode was citric acid, and it was a new full organic electrochemical system. By DFT calculation, it is determined that the sodium-oxygen binding energy of sodium tert-pentoxide is 58 kcal/mol, indicating that sodium tert-pentoxide can release electrons in electrochemical reaction. The existence of stable sodiation state at room temperature is a necessary condition for the negative electrode material of organic primary battery, and sodium tert-pentoxide meets this condition. The positive citric acid was prepared from fruit lemon, which was green and environment-friendly. The voltage of the organic primary battery is 1.1 V and the capacity is 79 mAhg−1. Because both positive and negative materials are organic materials, the waste of organic primary batteries is easier to deal with than inorganic primary batteries.