Perforated Metal Oxide-Carbon Nanotube Composite Microspheres with Enhanced Lithium-Ion Storage Properties

Metal oxide - carbon nanotube (CNT) composite microspheres with a novel structure were fabricated using a one-step spray pyrolysis process. Metal oxide - CNT composite microspheres with a uniform distribution of void nanospheres were prepared from a colloidal spray solution containing CNTs, metal salts, and polystyrene (PS) nanobeads. Perforated SnO₂ - CNT composite microspheres with a uniform distribution of void nanospheres showed excellent lithium storage properties as anode materials for lithium-ion batteries. Bare SnO₂ microspheres and SnO₂ - CNT composite microspheres with perforated and filled structures had a discharge capacity of 450, 1108, and 590 mA h g^-1 for the 250th cycle at a current density of 1.5 A g^-1, and the corresponding capacity retention compared to the second cycle was 41, 98, and 55%, respectively. The synergetic combination of void nanospheres and flexible CNTs improved the electrochemical properties of SnO₂. This effective and innovative strategy could be used for the preparation of perforated metal oxide-CNT composites with complex elemental compositions for many applications.