Phenolic Resins Based Activated Carbon As Electrode Material For Supercapacitors

The supercapacitor,which is one of the most significant energy stores,mainly consists of the electrical double-layer capacitors?EDLCs?and the pseudocapacitors according to the energy storage mechanism.As a class of electrode material,activated carbon?AC?draws increasing attention due to its high surface area,special pore structure and large pore volume.In this paper,phenolic resins were utilized as carobon resources,while KOH and ZnCl₂ as activators to prepare AC whose electrochemical performances were investigated in detail.The main work of this paper is as follows:?1?KOH activation:according to the process of phenolic resins'preparation?pre-polymerization-curing-carbonization?,KOH was added at different stage:after pre-polymerization?AC-1?,after curing?AC-2?and after carbonization?AC-3?.The results show that the electrochemical performances of sample AC-1 is much better than AC-2 and AC-3.And then phenol quality remained the same,the amount of KOH ranged from a quarter to quatruble of phenol quality.After several experiments,the results showed that when mass ratio between phenol and KOH is 1 to 1,the sample performed best:high specific capacity(specific capacity of the sample is 361.5 F·g^-1 when current density is 0.2A·g^-1)and great rate capability(specific capacity of the sample is 273.1 F·g^-1 when current density is 2.0 A·g^-1,75.8%of capacity is remained).Finally,this paper investigated influence of carbonization temperature on material performance.When the mass ratio between phenol and KOH remained 1 to 1 and carbonization temperature is 900 ^oC,the electrochemical performance is the better than the temperature 700 ^oC,800 ^oC and 1000 ^oC.?2?ZnCl₂ as activator was added at different stages of the experiment:after pre-polymerization?AC-4?,after curing?AC-5?and after carbonization?AC-6?.The results show the electrochemical performance of AC-4 is much better than AC-5 and AC-6.And then phenol quality remained the same,the amount of ZnCl₂ ranged from a quarter to quatruble of phenol quality.After several experiments,the results showed that when mass ratio between phenol and KOH is 1 to 3,the sample performed best:high specific capacity(specific capacity of the sample is 192.5 F·g^-1 when current density is 0.1 A·g^-1)and great rate capability(specific capacity of the sample is 175.3 F·g^-1 when current density is 2.0A·g^-1,91.4%of capacity is remained).