Study On The Strategy Of Improving Battery Performance By Inhibiting The Dissolution Of Organic Electrode Materials

Organic batteries are a new type of energy storage power source with application prospects,but they always suffer from the problem of organic electrode materials dissolving in electrolytes.The dissolution and shuttle effect of electrode materials will lead to the decrease of capacity,coulombic efficiency and cyclability.All of these severely limit the development and practical application of organic batteries,so it is urgent to inhibit the dissolution of organic electrode materials.Common strategies for inhibiting the dissolution of electrode materials include adding a protective film between the electrode and the electrolyte,preparing polymer electrode materials and so on.Inspired by the previous work,we prepared a free-standing dense protective film（PPF）blended by poly（3,4-ethylenedioxythiophene）-poly（styrene sulfonate）（PEDOT:PSS）and polyethylene oxide（PEO）.We can control the thickness of PPF protective film and the effect of inhibiting dissolution by adjusting the ratio of PEDOT:PSS and PEO.At the same time,we use the typical organic active material 5,7,12,14-pentacenetetrone（PT）as an example to check the performance of the protective film.The results show that the protective film can effectively inhibit the dissolution of small molecular electrode materials and improve the cyclability of the battery(the capacity of the PT electrode is stable at 201.4 m Ah g^-1 after 100 cycles).It is worth noting that this method can not only inhibit the dissolution and shuttle effect of electrode materials effectively,but also greatly simplify the production process of the protective film,so that the protective film may be used in industrial production.At the same time,this method can be applied to the protection of different organic electrode materials.Using polymers as electrode materials is also an effective method to reduce the solubility of electrode materials.This method is usually used in quinone-based organic electrode materials,but their discharge voltage is generally low,which is difficult to meet people’s demand for high-voltage batteries.5,10-dimethyldihydrophenazine（DMPZ）is a new type of cathode material with high capacity and high voltage,but it faces the problem of dissolution in the electrolyte too.This problem can be solved effectively by polymerizing it into polymer:poly（N,N’-dimethyl-5,10-dihydrophenazine）（p-DMPZ）.The p-DMPZ is obtained by polymerizing DMPZ along the end-position,and there is no inactive linking group in the polymer after polymerization.This polymerization method successfully avoids the introduction of inactive linking group and increases the capiacity of the electrode.The obtained capacity is up to 154 m Ah g^-1（at the rate of 2C）.P-DMPZ solved the problem of dissolution successfully and improved the electrochemical performance of the batteries.