Chi660e electrochemistry workstation

All the electrochemical experiments were conducted with a CHI660E electrochemistry workstation (Shanghai Chenhua Instruments Co., China). Electrochemical gaps were determined from the cyclic voltammetry (CV) experiments which were employed in dehydrated and deoxygenated dichloromethane (0.1 M Bu₄NPF₆ as the supporting electrolyte). A platinum foil (1 × 5 mm) was used as the auxiliary electrode and an Ag/AgCl electrode as the reference electrode. The LP/GCE (10 μL solution containing LP assemblies drop-cast onto GCE with a diameter of 5 mm) or PANI/GCE was used as the working electrode. Then the CV scan potential sweep range of −1.8 V–1.8 V, the scanning speed of 50 mV/s, and Eox,onset and Ered, onset determined from the onset potentials of the oxidation and reduction waves respectively. All cyclic voltammograms were calibrated against Fc/Fc⁺ redox couple in respective solvents. The electrochemical gap is calculated from the difference of oxidation and reduction potentials, and the calculation formula is as follows: $E_{HOMO}^{elec}=-\left(E_{ox,onset}+4.8\right)eV;E_{LUMO}^{elec}=-\left(E_{red,onset}+4.8\right)eV$

Polyvinylidene fluoride binder (10 wt%), 20 wt% carbon black, and 70 wt% active material (TiO₂/N–C NFs or TiO₂–C NFs) were dissolved in an appropriate amount of N-methyl-2-pyrrolidinone. The obtained slurry was evenly coated on copper foil and placed in a vacuum oven at 110 °C for 12 h. Circular pieces 1 cm in diameter were punched from the dried copper foil and used as working electrodes; their mass load was 1.2 ± 0.2 mg cm⁻². In an argon-filled glove box, CR2025-type coin cells were assembled; metallic sodium was used as the counter electrode and separated from the work electrode by a glass fiber (Whatman, GF/C). The electrolyte was a solution of 1 mol L⁻¹ NaClO₄ dissolved in propylene carbonate/ethylene carbonate (1:1 by volume). The coin cells were cycled in galvanostatic discharge–charge measurements using a battery testing system (Neware, China) at room temperature at voltage intervals of 0.01 and 2.5 V. Both cyclic voltammetry (CV) tests and electrochemical impedance spectroscopy (EIS) experiments were conducted on a CHI660E electrochemistry workstation (Chenhua, Shanghai).