The novel conductive polyaniline/bacterial cellulose (PANI/BC) nanocomposite membranes have been synthesized in situ by oxidative polymerization of aniline with ammonium persulfate as an oxidant and BC as a template. The resulting PANI-coated BC nanofibrils formed a uniform and flexible membrane. It was found that the PANI nanoparticles deposited on the surface of BC connected to form a continuous nanosheath by taking along the BC template, which greatly increases the thermal stability of BC. The content of PANI and the electrical conductivity of composites increased with increasing reaction time from 30 to 90 min, while the conductivity decreased because of the aggregation of PANI particles by further prolonging the reaction time. In addition, the acids remarkably improve the accessibility and reactivity of the hydroxyl groups of BC. The results indicate that the composites exhibit excellent electrical conductivity (the highest value was 5.0 × 10(-2) S/cm) and good mechanical properties (Young's modulus was 5.6 GPa and tensile strength was 95.7 MPa). Moreover, the electrical conductivity of the membrane is sensitive to the strain. This work provides a straightforward method to prepare flexible films with high conductivity and good mechanical properties, which could be applied in sensors, flexible electrodes, and flexible displays. It also opens a new field of potential applications of BC materials.

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Bacterial cellulose (BC) nanofibers represent an emerging class of highly crystalline bionanofibers with high intrinsic mechanical properties. The remarkable nanofibers with oriented structure and strong interfibrillar interactions can realize high-performance materials. In this study, we demonstrated that macrofibers based on aligned BC nanofibers could be prepared by wet spinning and drawing procedures. The relationship between process conditions, structure, and mechanical properties of macrofibers were investigated. The obtained macrofibers exhibited Young's modulus of 16.4 GPa and tensile strength of 248.6 MPa under the optimum process conditions, in which nanofibers displayed a high degree of alignment. Furthermore, we enhanced the interfacial interactions between nanofibers and obtained better mechanical performance by multivalent ion cross-linking. After exchanging the monovalent Na by Fe, the dried macrofiber reached Young's modulus of 22.9 GPa and tensile strength of 357.5 MPa. Particularly, the resulting macrofibers still maintained good mechanical properties with Young's modulus of 15.9 GPa and tensile strength of 262.2 MPa in the wet condition. This research provided a good method to fabricate macrofibers from BC nanofibers with good properties by continuous wet-spinning process. These macrofibers can be easily functionalized and have promising potential applications in smart textiles, biosensor, and structural reinforcement.

The structures and components of solid electrolyte interphase (SEI) are extremely important to influence the performance of full cells, which is determined by the formulation of electrolyte used. However, it is still challenging to control the formation of high‐quality SEI from structures to components. Herein, we designed bisfluoroacetamide (BFA) as the electrolyte additive for the construction of a gradient solid electrolyte interphase (SEI) structure that consists of a lithophilic surface with C−F bonds to uniformly capture Li ions and a LiF‐rich bottom layer to guide the rapid transportation of Li ions, endowing the homogeneous deposition of Li ions. Moreover, the BFA molecule changes the Li+ solvation structure by reducing free solvents in electrolyte to improve the antioxidant properties of electrolyte and prevent the extensive degradation of electrolyte on the cathode surface, which can make a superior cathode electrolyte interphase (CEI) with high‐content LiF.

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