A　novel　in　situ　self-catalyzed　synthetic　strategy　is　explored　to　prepare　graphitic　carbon　nanotubes　(CNTs)　wrapped　and　amorphous　nanocarbon　shells　coated　LiFePO4　microclews　(LiFePO4@C@CNT)　at　one-step.　The　formation　mechanism　of　CNTs　entangled　LiFePO4@C　microclews　is　investigated　by　X-ray　diffraction,　scanning　electron　microscopy　and　transmission　electron　microscopy.　The　results　show　that　the　in　situ　intergrowths　of　CNTs　and　LiFePO4@C　could　be　realized　by　the　catalytic　effect　of　Fe3C　nanoparticles　based　on　the　tip-growth　mechanism.　The　as-prepared　LiFePO4@C@CNT-5　composite　with　a　low　carbon　content　of　5　wt%,　an　optimum　composition　of　graphitic　CNTs　and　amorphous　carbon　shells　(ID/IG　=　0.9),　a　specific　surface　area　of　83　m2　g-1　and　an　electronic/ionic　conductivity　of　0.68　S　cm-1/2.1　x　10-12　cm2　s-　1　delivers　a　stable　discharge　capacity　of　158.2　mAh　g-1　at　0.1　C,　outstanding　rate　capability　of　136.1　mAh　g-1　at　1　C　and　remarkable　long-term　cycling　stability　of　129.6　mAh　g-1　after　1000　cycles　at　1　C,　indicating　a　promising　application　in　high-power　lithium-ion　batteries.　The　combined　good　electronic-ionic　conductivity　of　twisted　carbon　nanotubes　and　porous　nanocarbon　shells　and　robust　mechanical　stability　of　geometrically　confined　LiFePO4　particles　within　dual　nanocarbon　matrices　contribute　to　the　excellent　electrochemical　performance　of　LiFePO4@C@CNT.