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Recyclable conjugated polymers are important for realizing eco‐friendly electronics with advantages of solution processability and flexibility. A recyclable conjugated polymer, PY‐TIP is developed, of which a key monomer is successfully extracted via a mild depolymerization process and is reused for the synthesis of novel conjugated polymers. One‐shot preparation of polymer acceptor and its bulk‐heterojunction (BHJ) is demonstrated from the recycled monomer, Y5‐TA, for the first time and the resulting BHJ film shows optimal nanoscale morphology for efficient charge generation and transport. As a result, the solar cells prepared using the BHJ film show a higher efficiency of 13.08% and much improved thermal and mechanical stability compared with those based on the small molecular acceptor. These results are important in that the various polymers can be prepared from the recycled monomer in a solid state without organic solvents and purification step and this strategy is effective for improving the thermal and mechanical stability of the BHJ film as well as achieving high photovoltaic performance. PY‐TIP is exemplary in that it can reproduce its monomer which can be used to synthesize conjugated polymers with novel chemical structures and physical properties. This work provides a design guideline for developing recyclable conjugated polymers with dynamic covalent bonds. [ABSTRACT FROM AUTHOR]

Discrete dimer or multimer acceptors have enhanced the stability of organic solar cells (OSCs) due to their slow diffusion kinetics resulting from their large molecular sizes. However, development of multimer acceptors with chain length longer than trimers has been challenging, which often require multistep reactions with low synthetic yield. In this study, a new discrete tetramer acceptor (TetA) using one‐pot reaction and subsequent purification processes is developed. During the purification, dimer (DA) and trimer acceptor (TA) are also obtained. The OSCs for TetA demonstrate a higher power conversion efficiency (PCE) of 16.14% than those for the discrete acceptors with shorter chain lengths, such as monomer acceptor (MA, 12.85%), DA (14.31%), and TA (15.10%). Additionally, despite having a similar number‐average molecular weight, TetA‐based OSCs exhibit a significantly higher PCE (16.14%) compared to OSCs based on a mixture of the acceptors (MixA) with dispersity (10.72%). Furthermore, the TetA‐based OSCs have the highest photostability and mechanical robustness among the series. For example, TetA‐based OSCs demonstrate superior photostability (t70% lifetime = 2180 h under 1‐sun illumination) and mechanical robustness (crack‐onset strain (COS) = 8%) compared to those based on MA (t70% = 220 h, and COS = 2%), or MixA (t70% = 745 h, and COS = 6%). [ABSTRACT FROM AUTHOR]

A high-energy conversion efficiency of 8.2% at 100 mW cm−2 is reported, one of the highest values for N719-based, solid-state, dye-sensitized solar cells (ssDSSCs). The solar cells are based on hierarchical double-shell nanostructures consisting of inner SnO2 hollow spheres (SHS) surrounded by outer TiO2 nanosheets (TNSs). Deposition of the TNS on the SHS outer surface is performed via solvothermal reactions in order to generate a double-shell SHS@TNS nanostructure that provides a large surface area and suppresses recombination of photogenerated electrons. An organized mesoporous (OM)-TiO2 film with high porosity, large pores, and good interconnectivity is also prepared via a sol-gel process using a poly(vinyl chloride)-g-poly(oxyethylene methacrylate) (PVC-g-POEM) graft copolymer template. This film is utilized as a matrix to disperse the double-shell nanostructures. Such nanostructures provide good pore-filling for solid polymer electrolytes, faster electron transfer, and enhanced light scattering, as confirmed by reflectance spectroscopy, incident photon-to-electron conversion efficiency (IPCE), and intensity-modulated photocurrent spectroscopy (IMPS)/intensity-modulated photovoltage spectroscopy (IMVS). [ABSTRACT FROM AUTHOR]

A solid-state dye-sensitized solar cell (ssDSSC) with 7.4% efficiency at 100 mW/cm2 is reported. This efficiency is one of the highest observed for N719 dye. High performance is achieved via a honeycomb-like, organized mesoporous TiO2 photoanode with dual pores, high porosity, good interconnectivity, and excellent light scattering properties. The TiO2 photoanodes are prepared without any TiCl4 treatment via a one-step, direct self-assembly of hydrophilically preformed TiO2 nanocrystals and poly(vinyl chloride)- g-poly(oxyethylene methacrylate) (PVC- g-POEM) graft copolymer as a titania source and a structure-directing agent, respectively. Upon controlling the secondary forces between the polymer/TiO2 hybrid and the solvent by varying the amounts of HCl/H2O mixture or toluene, honeycomb-like structures are generated to improve light scattering properties. Such multifunctional nanostructures with dual pores provide good pore-filling of solid polymer electrolyte with large volume, enhanced light harvesting and reduced charge recombination, as confirmed by reflectance spectroscopy, incident photon-to-electron conversion efficiency (IPCE), and electrochemical impedance spectroscopy (EIS) analysis. [ABSTRACT FROM AUTHOR]

A new avenue by transforming the conventional electrochemical domain into an electro‐chemo‐mechanical domain is proposed to achieve less hysteretic fast‐charging based on the three pictures: i) electro‐chemo‐mechanics, ii) phase transition kinetics, and iii) ionic kinetics. Each concept is demonstrated leading to the electrochemical improvement using data‐driven computation and experimental analyses, and its novel framework is generalized based on alkali‐ion chalcogenide models. The mechanical strain lowers and delays the electrochemical yield point, which gives rise to extending the elastic region and enhancing the phase and ionic kinetics. This is experimentally verified with less hysteresis upon (dis)charging for all models. Implementing the electro‐chemo‐mechanical domain is central in alkali‐ion chalcogenide batteries and broadens its application in other rechargeable batteries, ultimately playing a critical role in providing practical fast‐charging solutions. [ABSTRACT FROM AUTHOR]