Wire-in-Wire TiO2/C Nanofibers Free-Standing Anodes for Li-Ion and K-Ion Batteries with Long Cycling Stability and High Capacity

Abstract

Wearable and portable mobile phones play a critical role in the market, and one of the key technologies is the flexible electrode with high specific capacity and excellent mechanical flexibility. Herein, a wire-in-wire TiO2/C nanofibers (TiO2 ww/CN) film is synthesized via electrospinning with selenium as a structural inducer. The interconnected carbon network and unique wire-in-wire nanostructure cannot only improve electronic conductivity and induce effective charge transports, but also bring a superior mechanic flexibility. Ultimately, TiO2 ww/CN film shows outstanding electrochemical performance as free-standing electrodes in Li/K ion batteries. It shows a discharge capacity as high as 303 mAh g−1 at 5 A g−1 after 6000 cycles in Li half-cells, and the unique structure is well-reserved after long-term cycling. Moreover, even TiO2 has a large diffusion barrier of K+, TiO2 ww/CN film demonstrates excellent performance (259 mAh g−1 at 0.05 A g−1 after 1000 cycles) in K half-cells owing to extraordinary pseudocapacitive contribution. The Li/K full cells consisted of TiO2 ww/CN film anode and LiFePO4/Perylene-3,4,9,10-tetracarboxylic dianhydride cathode possess outstanding cycling stability and demonstrate practical application from lighting at least 19 LEDs. It is, therefore, expected that this material will find broad applications in portable and wearable Li/K-ion batteries.

Porous Co2VO4 Nanodisk as a High-Energy and Fast-Charging Anode for Lithium-Ion Batteries

“…This phenomenon was observed in many transition oxides. The rapid capacity decrease is resulted from the conversion reactions, generated volume expansion and formation of SEI layer [ 16 , 25 , 34 , 42 ]. The subsequent capacity increase might be attributed to the increased crystallinity of active materials and gradual activation progress during the cycle [ 17 , 36 , 38 ].…”

Carbon‐Encapsulated Ni3Se4/CoSe2 Heterostructured Nanospheres: Sodium/Potassium‐Ion Storage Anode with Prominent Electrochemical Properties

“…[40,41] A diffusion-controlled process implies that b approaches 0.5, whereas a value of 1.0 implies a dominant capacitance-controlled process. [42,43] The calculated b values of the cathodic and anodic peaks are 0.79 and 0.62 (Figure 3f), respectively, based on the slope of log i versus Small 2022, 18, 2107258 log v curves. The specific capacitance contribution to the total storage at 0.1 mV s −1 was determined as 51.5%, which is represented by the green shaded area in Figure 3g.…”

Multicomponent Composite Membrane with Three-Phase Interface Heterostructure as Photocatalyst for Organic Dye Removal

“…The peaks at 464.0 and 458.0 eV corresponded to the Ti 4 + 2p 1/2 and Ti 4 + 2p 3/2 spin–orbital splitting photoelectrons at around 5.6 eV, respectively, suggesting that the Ti elements existed as the Ti 4 + state. 47 , 48 Figure 4 d shows the high-resolution XPS spectra of Si 2p. The peak at 101.5 eV was attributed to the Si(IV) chemical state, 49 implying that the SiO 2 aerogel was on the surface of P-S-T/C.…”