Silicon-Carbon Core-Shell Hollow Nanotubular Configuration High-Performance Lithium-Ion Anodes

Silicon anode systems, due to their intrinsic high theoretical specific capacity, show tremendous potential in lithium ion batteries (LIBs). Unfortunately, commercial application still remains elusive due to the cycling-related colossal volume expansion issues following Li alloying and dealloying. Herein, core-shell C@Si@C hollow nanotubes with optimal Si thickness (similar to 60 nm) showing no microstructural damage during lithiation and delithiation processes, have been developed as a stable anode for LIBs with low first-cycle irreversible loss (FIR) of similar to 13% and high areal capacity (similar to 3 mAhcm(-2)) for the first time. The hollow Si nanotubes (h-SiNTs) have been generated via our previously reported high-throughput and recyclable, sacrificial MgO wire template fabrication, approach. Generation of Si films of varying thickness by low-pressure thermal chemical vapor deposition (LPCVD) with subsequent etching yields h-SiNTs. Modification/optimization of the h-SiNT physical characteristics exhibit improved performance in LIBs. Carbon coating of optimized h-SiNTs further, yields core-shell h-SiNTs for the first time exhibiting not only low FIR. loss of similar to 13%, with a specific capacity of similar to 1000 mA.h.g(-1) at discharge/charge currents of similar to 1 A.g(-1) for over 120 cycles, but also a low fade rate of similar to 0.072% loss per cycle.