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Polyvinyl chloride (PVC) plastics are widely applicable in our daily life; however, their overuse and extremely high resistance to recycling/disposal have caused serious challenges to our environment. In this study, we proposed an effective and green method to convert PVC plastics to carbonaceous materials via KOH-assisted roomtemperature dehalogenation, along with the formation of clean byproducts of KCl and H 2 O. Thereof, high-quality porous carbon materials are obtainable through performing simple annealing on the above-mentioned carbonaceous materials. The as-resulted carbon materials derived from PVC plastics were fabricated into electrodes for supercapacitor application. Remarkably, the porous carbon material derived from PVC plastic wrap (PW-C) exhibited excellent performance for aqueous symmetric supercapacitor. The specific capacitance reached up to 399 and 363 F g −1 (at 1.0 A g −1 ) in 6.0 mol L −1 KOH and 1.0 mol L −1 H 2 SO 4 electrolytes, respectively. Meanwhile, PW-C showed very good rate capability and cycling stability in both electrolytes. Therefore, our developed method is capable of treating PVC plastic wastes safely and efficiently and converting them into valued-added porous carbon electrode materials, which may find very soon practical implantations.

Doped carbon materials (DCM) with multiple heteroatoms hold broad interest in electrochemical catalysis and energy storage but require several steps to fabricate, which greatly hinder their practical applications. In this study, a facile strategy is developed to enable the fast fabrication of multiply doped carbon materials via room-temperature dehalogenation of polyvinyl dichloride (PVDC) promoted by KOH with the presence of different organic dopants. A N,S-codoped carbon material (NS-DCM) is demonstratively synthesized using two dopants (dimethylformamide for N doping and dimethyl sulfoxide for S doping). Afterward, the precursive room-temperature NS-DCM with intentionally overdosed KOH is submitted to inert annealing to obtain large specific surface area and high conductivity. Remarkably, NS-DCM annealed at 600 °C (named as 600-NS-DCM), with 3.0 atom % N and 2.4 atom % S, exhibits a very high specific capacitance of 427 F g at 1.0 A g in acidic electrolyte and also keeps ∼60% of capacitance at ultrahigh current density of 100.0 A g. Furthermore, capacitive deionization (CDI) measurements reveal that 600-NS-DCM possesses a large desalination capacity of 32.3 mg g (40.0 mg L NaCl) and very good cycling stability. Our strategy of fabricating multiply doped carbon materials can be potentially extended to the synthesis of carbon materials with various combinations of heteroatom doping for broad electrochemical applications.

Li metal is considered to be the most attractive anode for next-generation batteries because of its high specific capacity and low reduction potential. However, uncontrolled Li dendrite growth and low Coulombic efficiency cause severe capacity decay and safety issues. Here we propose a LiCl contained inorganic−organic hybrid layer on Li metal surface by a surface restraint dehalogenation reaction, which is highly uniform and features lithiophilic property as well as high ionic conductivity that can inhibit Li dendrite growth effectively. Consequently, the surface protected Li metal electrodes enable Li | Li symmetric cells to maintain a stable and low overpotential of 20 mV at a current density of 1 mA cm −2 after cycling over 3000 h, and enable Li | LiFePO 4 pouch cell to decay only 0.05% in capacity per cycle at 5.0 C for 500 cycles, indicating excellent cycle stability and high rate capability. This work offers a simple and facile method to protect Li metal anode and promise a potential direction for industrialization of Li metal batteries.