Electrospinning is an effective and versatile method to prepare continuous polymer nanofibers and nonwovens that exhibit excellent properties such as high molecular orientation, high porosity and large specific surface area. Benefitting from these outstanding and intriguing features, electrospun nanofibers have been employed as a promising candidate for the fabrication of food packaging materials. Actually, the electrospun nanofibers used in food packaging must possess biocompatibility and low toxicity. In addition, in order to maintain the quality of food and extend its shelf life, food packaging materials also need to have certain functionality. Herein, in this timely review, functional materials produced from electrospinning toward food packaging are highlighted. At first, various strategies for the preparation of polymer electrospun fiber are introduced, then the characteristics of different packaging films and their successful applications in food packaging are summarized, including degradable materials, superhydrophobic materials, edible materials, antibacterial materials and high barrier materials. Finally, the future perspective and key challenges of polymer electrospun nanofibers for food packaging are also discussed. Hopefully, this review would provide a fundamental insight into the development of electrospun functional materials with high performance for food packaging.

Organic carbonyl compounds have achieved great success as prospective electrodes for rechargeable metal-ion batteries for the replacement of commercial inorganic electrodes, since the extensive chemistry of organics allows to vary the structure in an eco-friendly manner to tune electrochemical properties. However, the ease of dissolution in electrolyte, intrinsically poor electronic conductivity, and low volumetric energy density greatly restrict their long-term cyclability and rate capability, impeding their widespread usage, especially for practical battery systems. Considering this, a great number of molecular engineering strategies have been proposed to overcome the above obstacles. In this review, we have summarized several commonly used molecular engineering approaches to reinforce the electrochemical performance of carbonyl organic compounds and simultaneously generalized the advantages and disadvantages of each strategy. Some recent key investigations on the reaction mechanism of carbonyl organic electrodes by using operando and ex situ techniques as well as theoretical calculations have also been highlighted. More importantly, different from most of the previous reviews focused on materials design, some critical challenges and future perspectives of carbonyl organic electrodes for practical battery systems have been evaluated in more depth. Therefore, this review will offer fundamental and useful guidance not only for the rational design of carbonyl electrodes but also for practical carbonyl-based battery systems applicable in the foreseeable future.

Superlithiation has been observed in some carbonyl-based organic electrodes, which leads to very high battery capacity. However, as typical carbonyl polymers, polyimides (PIs) exhibited a relatively low capacity (≤250 mA h g⁻¹) in previous studies because their poor electrical conductivity restricts superlithiation. Therefore, to realize superlithiation, in this study, multilayer graphene (MG) as a conductive additive was incorporated in PI matrix through a blending precipitation and thermal imidization method. As an electrode in lithium-ion batteries, PI–MG exhibited outstanding capacity (612 mA h g⁻¹ at 100 mA g⁻¹) and stable long-term cyclability (89.3% capacity retention over 500 cycles at 500 mA g⁻¹). Moreover, the battery could be operated stably at various temperatures, and it exhibited very high specific capacity, especially at the high operating temperature of 55 °C (873 mA h g⁻¹, 0.1C). We believe that this strategy of introducing conductive additives to promote superlithiation is highly applicable to other non-conductive carbonyl polymers for lithium-ion battery applications.