Flexible piezoresistive sensors with high sensitivity, low cost, and wide response ranges are urgently required due to the rapid development of wearable electronics. Here, carbon nanotubes (CNTs)/graphene/waterborne polyurethane (WPU)/cellulose nanocrystal (CNC) composite aerogels (CNTs/graphene/WC) were fabricated by facile solution mixing and freeze-drying technology for high-performance pressure sensors. WPU and CNC were constructed as a 3D structure skeleton, and the synergistic effect of CNTs and graphene was beneficial to enhancing the sensing performance. The obtained pressure sensor exhibits a highly porous network structure, remarkable mechanical properties (76.16 kPa), high sensitivity (0.25 kPa–1), an ultralow detection limit (0.112 kPa), and high stability (>800 cycles). More importantly, the piezoresistive sensor could be successfully used to detect various human motions such as finger bending, squatting–rising, walking, and running and effectively extract real-time information by the electrical signals. In addition, the CNTs/graphene/WC composite aerogel exhibits excellent thermal insulation performance, which can withstand 160 °C for a long time without any damage to the structure. The CNTs/graphene/WC composite aerogel, because of its thermal insulation property, endows the sensor with the potential for application in high-temperature environments. The results indicate that CNTs/graphene/WC composite aerogels possess high sensing performance and outstanding thermal insulation, which means that the aerogels could be used as flexible, wearable electronics.

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Zn and Co oxides possess high theoretical capacity; however, their application in the field of lithium-ion batteries (LIBs) is greatly limited because of poor conductivity and large volume fluctuation. Herein, the multi-protuberant nanofiber structure was formed by combining two-dimensional (2D) Ti 3 C 2 nanosheets and zero-dimensional (0D) ZnCo 2 O 4 nanoparticles on the surface and inside one-dimensional (1D) carbon nanofibers (Ti 3 C 2 @ZnCo 2 O 4 @carbon nanofibers) for lithium-ion storage. The Ti 3 C 2 @ZnCo 2 O 4 @carbon nanofiber composite prepared by electrospinning, annealing, and oxidation at low temperature provides abundant active sites and an efficient conductive network to enhance the storage capacity and transfer rate of lithium ions. The Ti 3 C 2 @ZnCo 2 O 4 @carbon nanofiber anode provides high reversible specific capacity (1112.51 mA h g −1 at 0.2 A g −1 ), outstanding cycle stability (603.796 mA h g −1 at 0.5 A g −1 after 300 cycles), and excellent rate performance (455.05 mA h g −1 at 3 A g −1 and maintains 920.17 mA h g −1 when current is restored to 0.1 A g −1 ). The remarkable Li storage originates from the stable multiprotuberant nanofiber structure and fast electrochemical kinetics. The unique structure design of Ti 3 C 2 @ZnCo 2 O 4 @carbon nanofibers also provides an effective strategy for other electrochemical fields.