Ordered Network of Interconnected SnO2 Nanoparticles for Excellent Lithium-Ion Storage

An ordered network of interconnected tin oxide (SnO2) nanoparticles with a unique 3D architecture and an excellent lithium-ion (Li-ion) storage performance is derived for the first time through hydrolysis and thermal self-assembly of the solid alkoxide precursor. Mesoporous anodes composed of these approximate to 9 nm-sized SnO2 particles exhibit substantially higher specific capacities, rate performance, coulombic efficiency, and cycling stabilities compared with disordered nanoparticles and commercial SnO2. A discharge capacity of 778 mAh g(-1), which is very close to the theoretical limit of 781 mAh g(-1), is achieved at a current density of 0.1 C. Even at high rates of 2 C (1.5 A g(-1)) and 6 C (4.7 A g(-1)), these ordered SnO2 nanoparticles retain stable specific capacities of 430 and 300 mAh g(-1), respectively, after 100 cycles. Interconnection between individual nanoparticles and structural integrity of the SnO2 electrodes are preserved through numerous charge-discharge process cycles. The significantly better electrochemical performance of ordered SnO2 nanoparticles with a tap density of 1.60 g cm(-3) is attributed to the superior electrode/electrolyte contact, Li-ion diffusion, absence of particle agglomeration, and improved strain relaxation (due to tiny space available for the local expansion). This comprehensive study demonstrates the necessity of mesoporosity and interconnection between individual nanoparticles for improving the Li-ion storage electrochemical performance of SnO2 anodes.