Reinforcing effect of single-wall carbon nanotubes on the LiNi0.6Co0.2Mn0.2O2 composite cathode for high-energy–density all-solid-state Li-ion batteries

[Display omitted] •Cathode (NCM-CNT) was composed of LiNi0.6Co0.2Mn0.2O and single wall carbon nanotubes (SWCNTs).•Small content of SWCNT in LiNi0.6Co0.2Mn0.2O afford continuous pathway for electron transportation.•The Li/CSPE/NCM-CNT cell delivered high areal discharge capacity of 2.48 mAh cm−2 at 0.5C.•All-solid state Li-ion batteries (ASSLIBs) delivered high areal capacity of 4.04 mAh cm−2 at 0.5C. Enhancing the effective electronic transportation pathways and high loading mass of cathode are the challenges for high energy density solid-state batteries. We successfully enhanced significantly the electrochemical characteristics of all-solid-state Li-ion battery (ASSLIB) composed of graphite/SiOx anode, PVDF-HFP/Al2O3 based composite solid polymer electrolyte (CSPE), and LiNi0.6Co0.2Mn0.2O2 cathode with high proportion of 96.94 wt% in cathode by employing only small amount (0.06 wt%) of SWCNT in electrodes. The Li/CSPE/NCM@CNT cell maintained a capacity of 2.31 mAh cm−2 at rate of 0.5C with a capacity retention of ~ 93% over 50 cycles. Moreover, The Li/CSPE/G-SiOx@CNT cell delivered an areal charge capacity of 3.7 mAh cm−2 at a rate of 0.5C. Furthermore, the ASSLIBs with a high cathode mass loading of 36.4 mg cm−2 delivered a high areal capacity of 4.04 mAh cm−2 and successfully operated for longer than 300 cycles at rate of 0.5C. The ASSLIBs show excellent cyclability with capacity retention of ~ 80% and coulombic efficiency of approximately 100%, even at a considerably high cathode mass loading of 36.4 mg cm−2 at a rate of 0.5C. The SWCNT form a conductive network throughout the electrodes by providing prolonged electron transport pathways and enhance the overall electrochemical properties of ASSLIBs.