NiCo-Layered Double Hydroxide Nanosheet/Carbonized Bacterial Cellulose Aerogel for Lithium-Ion Storage

Lithium-ion hybrid capacitors (LIHCs) have garnered significant attention in recent years because of their high energy and power density. In a proof-of-concept design, ZIF-67 nanoparticles were grown on the skeleton of carbonized bacterial cellulose (CBC) aerogel. Then, nickel cobalt layered double hydroxide (NiCo-LDH) nanosheets were formed via in situ etching-induced conversion of ZIF-67. The resulting free-standing NiCo-LDH/CBC composite not only presents a three-dimensional network to enhance the conductivity and alleviate volume variation, but is also favorable for exposing abundant active sites to increase the lithium-ion storage behavior. Consequently, the obtained free-standing NiCo-LDH/CBC aerogel displays outstanding cycling performance (673 mAh g–1 at 1 A g–1 after 1000 cycles). Furthermore, the fabricated NiCo-LDH/CBC||KCBC LIHC achieves a high energy density (88 Wh kg–1) at a high power density of 10.5 kW kg–1 and an excellent capacity retention of approximately 83% after 10,000 cycles at 2 A g–1, the performance of which makes the obtained free-standing aerogel a promising electrode for advanced wearable LIHC systems.