Peripheral octamethyl-substituted nickel(Ⅱ)-phthalocyanine-decorated carbon-nanotube electrodes for high-performance all-solid-state flexible symmetric supercapacitors

Construction of advanced electrode materials with unique performance for supercapacitors(SCs)is essential to achieving high implementation in the commercial market.Here,we report a novel peripheral octamethyl-substituted nickel(Ⅱ)phthalocyanine(Ni Me_(2)Pc)-based nanocomposite as the electrode material of all-solid-state SCs.The highly redox-active NiMe_(2)Pc/carboxylated carbon nanotube(CNTCOOH)dendritic nanocomposite provides rapid electron/electrolyte ion-transport pathways and exhibits excellent structural stability,resulting in high-capacity activity and impressive cycling stability.The composite prepared with the optimized weight ratio of Ni Me_(2)Pc:CNT-COOH(6:10)showed the highest specific capacitance of 330.5 F g^(-1)at 0.25 A g^(-1).The constructed NiMe_(2)Pc/CNT-COOH-based all-solid-state symmetric SC device showed excellent performance with a maximum energy density of 22.8 Wh kg^(-1)and outstanding cycling stability(111.6%retained after 35,000 cycles).Moreover,flexible carbon cloth significantly enhanced the energy density of the NiMe_(2)Pc/CNT-COOH all-solid-state symmetric device to 52.1 Wh kg^(-1)with 95.4%capacitance retention after 35,000 cycles,and it could be applied to highperformance flexible electronics applications.These findings provide a novel strategy to design phthalocyanine-based electrode materials for next-generation flexible SC devices.

Boosting the Capacitive Performance of Cobalt(Ⅱ) Phthalocyanine by Non-peripheral Octamethyl Substitution for Supercapacitors

In this paper,pristine cobalt(Ⅱ)phthalocyanine(CoPc)and non-peripheral octamethyl substituted CoPc(N-CoMe_(2)Pc)are the focus of electrochemical investigation.CoPc and N-CoMe_(2)Pc nanorods(NR)were synthesized by a facile precipitation process from sublimated bulk phthalocyanine powders and their electrochemical properties were explored.Due to the large specific surface area,the capacitance performance of the nanorods was significantly higher than that of the sublimated powder sample.N-CoMe_(2)Pc powder exhibited better pseudocapacity compared with CoPc powder and CoPc NR,which is attributed to enhanced charge transfer rate and im-proved redox activity after the introduction of octamethyl substituents on phthalocyanine ring.The maximum specific capacitance value was achieved by N-CoMe_(2)Pc NR based electrode,exhibiting 210.2 F g^(-1) capacitance at 5 mV s^(-1) scan rate and 156.1 F g^(-1) at 0.25 A g^(-1) current density,and also showing high efficiency and satisfactory retention.These results indicate that according to proper molecular design,N-CoMe_(2)Pc NR could be applied as the potential candidate for electrode material in supercapacitors.