Heteroatom-doped porous carbon materials (HPCMs) have found extensive applications in adsorption/separation, organic catalysis, sensing, and energy conversion/storage. The judicious choice of carbon precursors is crucial for the manufacture of HPCMs with specific usages and maximization of their functions. In this regard, polymers as precursors have demonstrated great promise because of their versatile molecular and nanoscale structures, modulatable chemical composition, and rich processing techniques to generate textures that, in combination with proper solid-state chemistry, can be maintained throughout carbonization. This Review comprehensively surveys the progress in polymer-derived functional HPCMs in terms of how to produce and control their porosities, heteroatom doping effects, and morphologies and their related use. First, we summarize and discuss synthetic approaches, including hard and soft templating methods as well as direct synthesis strategies employing polymers to control the pores and/or heteroatoms in HPCMs. Second, we summarize the heteroatom doping effects on the thermal stability, electronic and optical properties, and surface chemistry of HPCMs. Specifically, the heteroatom doping effect, which involves both single-type heteroatom doping and codoping of two or more types of heteroatoms into the carbon network, is discussed. Considering the significance of the morphologies of HPCMs in their application spectrum, potential choices of suitable polymeric precursors and strategies to precisely regulate the morphologies of HPCMs are presented. Finally, we provide our perspective on how to predefine the structures of HPCMs by using polymers to realize their potential applications in the current fields of energy generation/conversion and environmental remediation. We believe that these analyses and deductions are valuable for a systematic understanding of polymer-derived carbon materials and will serve as a source of inspiration for the design of future HPCMs.

Lithium-ion batteries (LIBs) have been demonstrated as one of the most promising energy storage devices for applications in electric vehicles, smart grids, large-scale energy storage systems, and portable electronics.

Multifunctional Ti4O7 particles with interconnected‐pore structure are designed and synthesized using porous poly(styrene‐b‐2‐vinylpyridine) particles as a template. The particles can work efficiently as a sulfur‐host material for lithium–sulfur batteries. Specifically, the well‐defined porous Ti4O7 particles exhibit interconnected pores in the interior and have a high‐surface area of 592 m2 g−1; this shows the advantage of mesopores for encapsulating of sulfur and provides a polar surface for chemical binding with polysulfides to suppress their dissolution. Moreover, in order to improve the conductivity of the electrode, a thin layer of carbon is coated on the Ti4O7 surface without destroying its porous structure. The porous Ti4O7 and carbon‐coated Ti4O7 particles show significantly improved electrochemical performances as cathode materials for Li–S batteries as compared with those of TiO2 particles.

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Limited understanding of the lithium (Li) nucleation and growth mechanism has hampered the implementation of Li-metal batteries. Herein, we unravel the evolution of the morphology and inner structure of Li deposits using focused ion beam scanning electron microscopy (FIB/SEM). Ball-shaped Li deposits are found to be widespread and stack up at a low current density. When the current density exceeds the diffusion-limiting current, bush-shaped deposition appears that consists of Li-balls, Li-whiskers, and bulky Li. Cryogenic transmission electron microscopy (cryo-TEM) further reveals that Li-balls are primarily amorphous, whereas the Li-whiskers are highly crystalline. Additionally, the solid electrolyte interface (SEI) layers of the Li-balls and whiskers show a difference in structure and composition, which is correlated to the underlying deposition mechanism. The revealed Li nucleation and growth mechanism and the correlation with the nanostructure and chemistry of the SEI provide insights toward the practical use of rechargeable Li-metal batteries.