CHU S,MAJUMDAR A.Opportunities and challenges for a sustainable energy future[J].Nature,2012,488(7411):294-303.

LIU D L,TONG Y Y,YAN X,et al.Recent advances in carbon-based bifunctional oxygen catalysts for zinc-air batteries[J].Batteries&Supercaps,2019,2(9):743-765.

DUNN B,KAMATH H,TARASCON J M.Electrical energy storage for the grid:a battery of choices[J].Science,2011,334(6058):928-935.

YAN X H,PRABHU P,XU H,et al.Recent progress of metal carbides encapsulated in carbon-based materials for electrocatalysis of oxygen reduction reaction[J].Small Methods,2019,4(1):1900575.

JORGE A B,JERVIS R,PERIASAMY A P,et al.3D carbon materials for efficient oxygen and hydrogen electrocatalysis[J].Advanced Energy Materials,2020,10(11):1902494.

XU G,XU G C,BAN J J,et al.Cobalt and cobalt oxides N-codoped porous carbon derived from metal-organic framework as bifunctional catalyst for oxygen reduction and oxygen evolution reactions[J].Journal of Colloid and Interface Science,2018,521:141-149.

HAN X P,ZHANG W,MA X Y,et al.Identifying the activation of bimetallic sites in Ni Co2S4@g-C3N4-CNT hybrid electrocatalysts for synergistic oxygen reduction and evolution[J].Advanced Materials,2019,31(18):1808281.

LI Y,SUN Y,QIN Y,et al.Recent advances on water-splitting electrocatalysis mediated by noble-metal-based nanostructured materials[J].Advanced Energy Materials,2020,10(11):1903120.

RATHINAVEL S,PRIYADHARSHINI K,PANDE D.A review on carbon nanotube:an overview of synthesis,properties,functionalization,characterization and the application[J].Materials Science&Engineering B,2021,268:115095.

TABASSUM H,MAHMOOD A,ZHU B J,et al.Recent advances in confining metal-based nanoparticles into carbon nanotubes for electrochemical energy conversion and storage devices[J].Energy&Environmental Science,2019,12(10):2924-2956.

CAO T,WANG D,ZHANG J T,et al.Bamboo-like nitrogen-doped carbon nanotubes with Co nanoparticles encapsulated at the tips:uniform and large-scale synthesis and high-performance electrocatalysts for oxygen reduction[J].Chemistry-A European Journal,2015,21(40):14022-14029.

LIU J Y,XU L,DENG Y L,et al.Metallic cobalt nanoparticles embedded in sulfur and nitrogen Co-doped rambutan-like nanocarbons for the oxygen reduction reaction under both acidic and alkaline conditions[J].Journal of Materials Chemistry A,2019,7(23):14291-14301.

WU B,MI J L,HU H,et al.Fe-,S-and N-doped carbon nanotube networks as electrocatalysts for the oxygen reduction reaction[J].ACS Applied Nano Materials,2020,3(12):12297-12307.