Lithium (Li) metal is a candidate anode for the next generation of high-energy density secondary batteries. Unfortunately, Li metal anodes (LMAs) are extremely reactive with electrolytes to accumulate uncontrolled dendrites and to generate unwanted parasitic electrochemical reactions. Much attention has been focused on carbon materials to address these issues. Ulteriorly, the failure mechanism investigation of lithiophilic sites on carbon materials has been not taken seriously. Herein, we design a new type of sesame ball-like carbon sphere (AgNPs@CS, an average diameter of ∼700 nm) with uniformly interfacial anchored silver nanoparticles (AgNPs), which is used as the dendrite-free Li metal anode host. This anchored structure significantly enhances reversible and chemical affinity of Li, effectively inhibiting "dead Li". In addition, the protective effect of the carbon layer can avoid the damage of lithiophilic AgNPs in the carbon matrix. With a plating/striping capacity of 2 mA h cm-2, the AgNPs@CS electrode can be cycled over 2400 h at 0.5 mA cm-2. When the stripping voltage increases to 1 V, the AgNPs@CS electrode also enables excellent cycling stability to achieve over 260 cycles (1 mA cm-2, 1 mA h cm-2) and 130 cycles (2 mA cm-2, 1 mA h cm-2). This material by electrochemical characterization highlights the efficacy of this facile method for developing dendrite-free LMAs.
Keywords: carbon spheres; lithium deposition; lithium metal anode; lithophilic site protection; silver nanoparticles.