Advanced rechargeable lithium-ion batteries based on bendable ZnCo₂O₄-urchins-on-carbon-fibers electrodes

A novel class of ZnCo₂O₄-urchins-on-carbon-fibers matrix has been designed, characterized, and used to fabricate high-performance energy storage devices. We obtained a reversible lithium storage capacity of 1180 mA·h/g even after 100 cycles, demonstrating the highreversible capacity and excellent cycle life of the as-prepared samples. Tested as fast-charging batteries, these electrodes exhibited a considerable capacity of 750 mA·h/g at an exceptionally high rate of 20 C (18 A/g), with an excellent cycle life (as long as 100 cycles), which are the best high-rate results reported at such a high charge/discharge current density for ZnCo₂O₄-based anode materials in lithium rechargeable batteries. Such attractive properties may be attributed to the unique structure of the binder-free ZnCo₂O₄-urchins-on-carbon-fibers matrix. Full batteries were also developed by combining the ZnCo₂O₄ anodes with commercial LiCoO₂ cathodes, which showed flexible/wearable and stable features for use as very promising future energy storage units. [Figure not available: see fulltext.]