Putting Nanoarmors on Yolk-Shell Si@C Nanoparticles: A Reliable Engineering Way To Build Better Si-Based Anodes for Li-Ion Batteries.

Practical utilization of silicon (Si) for Li-ion batteries (LIBs) still remains sluggish because of its formidable kinetic problems of huge volume expansions over 300%, instable solid electrolyte interphase (SEI), and unsatisfactory electrical conductivity. Though using a yolk-shell (Y-S) Si@C nanodesign indeed helps to mitigate active changes, optimize SEI properties, and lower intrinsic charge-transfer impedances, the total anodic behaviors in reversibility, rate capabilities, and long-lasting cyclability are still far from perfect. To settle the above issues, we herein propose a reliable and effective way by putting tough and malleable Ni nanoarmors on Y-S Si@C nanoparticles (Si@C⊆Ni). The unique functionalized configurations endow such hybrid systems with superb reversible capacity retention (almost no capacity decay emerges in 600 cycles, retaining a reversible capacity beyond ∼1307 mA h g-1 ), prominent cyclic stability, and rate behaviors. To justify their potential usage, full cells of (-)Si@C⊆Ni//LiFePO4 (+) are further constructed, delivering impressive specific energy and power densities (max.

VALUES: ∼423 W h kg-1 /∼497.8 W kg-1 ). This paradigm work may offer a highly feasible engineering protocol to push forward Si anode performances for next-generation LIBs.