Guiding confined deposition of lithium through the conductivity changing interface within a hierarchical heterostructure toward dendrite-free lithium anodes.

Although lithium metal has long been regarded as a promising anode material for high-energy density batteries due to its high specific capacity and low potential, the safety hazard caused by uncontrollable growth of lithium dendrites limited its practical applications. Herein, we developed a hierarchical heterostructure consisted of the carbon fiber cloth (CFC) core with good conductivity and the treated metal-organic frameworks (tMOFs) sheath with poor conductivity (CFC-tMOFs). In this structure, not only the conductivity changing interface trapped lithium inside the porous sheath, guiding uniform lithium nucleation, but also the tMOFs sheath served as a persistent buffer layer to confine subsequent deposition of lithium, avoiding the formation of lithium dendrites. Consequently, lithium dendrites were efficiently eliminated with a uniform lithium deposition of 5 mAh cm−2, and this matrix exhibited superior cycling stability with a high coulombic efficiency of 99% over 500 cycles with 1 mAh cm−2. A CFC-tMOFs matrix with the conductivity changing interface and hierarchical heterostructure is achieved. Such unique features not only enable to confined and homogenous deposition of lithium, but also resolved volume change of lithium during cycling process. Consequently, this matrix reveals superior cycling stability with a high coulombic efficiency of 99% over 500 cycles with 1 mAh cm−2. Image 1 • Developed a hierarchical heterostructure with superiorly conductive carbon fiber cores and poorly conductive tMOFs sheaths. • The heterostructure trapped lithium onto carbon fiber cores via the conductivity changing interface. • The tMOFs sheath as a persistent buffer layer confined lithium deposition, avoiding the formation of lithium dendrites. • The heterostructure shown superior cycling stability including a coulombic efficiency of 99% over 500 cycles with 1 mAh cm-2. [ABSTRACT FROM AUTHOR]