Chemical interaction motivated structure design of layered metal carbonate hydroxide/MXene composites for fast and durable lithium ion storage

Abstract

Rational architecture design has turned out to be an effective strategy in improving the electrochemical performance of electrode materials for batteries. However, an elaborate structure that could simultaneously endow active materials with promoted reaction reversibility, accelerated kinetic and restricted volume change still remains a huge challenge. Herein, a novel chemical interaction motivated structure design strategy has been proposed, and a chemically bonded Co(CO3)0.5OH·0.11H2O@MXene (CoCH@MXene) layered-composite was fabricated for the first time. In such a composite, the chemical interaction between Co2+ and MXene drives the growth of smaller-sized CoCH crystals and the subsequent formation of interwoven CoCH wires sandwiched in-between MXene nanosheets. This unique layered structure not only encourages charge transfer for faster reaction dynamics, but buffers the volume change of CoCH during lithiation-delithiation process, owing to the confined crystal growth between conductive MXene layers with the help of chemical bonding. Besides, the sandwiched interwoven CoCH wires also prevent the stacking of MXene layers, further conducive to the electrochemical performance of the composite. As a result, the as-prepared CoCH@MXene anode demonstrates a high reversible capacity (903.1 mAh g−1 at 100 mA g−1) and excellent cycling stability (maintains 733.6 mAh g−1 at 1000 mA g−1 after 500 cycles) for lithium ion batteries. This work highlights a novel concept of layer-by-layer chemical interaction motivated architecture design for futuristic high performance electrode materials in energy storage systems.