The preparation of whole sp-C composed alkyne rich carbon materials

For the high content of sp-hybridized carbon atoms, carbyne based materials can express superior conductivity and ultra-high theoretical capacity, which are key factors of high-performance anode. However, the poor stability of synthetic intermediates and unwanted side reactions lead to huge challenge to synthesis carbyne alternating carbon-carbon triple and single bonds. Here, we rationally designed a smart Greedy Snake strategy to synthesize the alkyne rich carbon materials named Si capped alkyne rich carbon (Si-Alkyne-C) which comprised of sp-hybridized carbon atoms. The as-prepared Si-Alkyne-C generated on the copper surface through a carbon-carbon coupling, in which Si can effectively protect the intermediates generated by the reaction. The C-Si bond can constantly generate copper-alkyne intermediates to couple with other terminal alkynes to continuously elongate like Greedy Snake, forming a long alkyne chain structure. The as-prepared Si-Alkyne-C can be applied as anode electrodes, exhibited very high reversible capacity of up to 2776 mAh/g at a current density of 50 mA/g and an average capacity around 1202 mAh/g at a high current density of 5000 mA/g for 5000 cycles, which are the best results among the reported carbon materials and better than many other anode materials. These results not only provide a facile strategy to prepare carbyne based materials, but also open a broad avenue for the preparation of high-capacity anode materials.

Automated summary

Due to the high content of sp-hybridized carbon atoms, carbyne based materials exhibit superior conductivity and ultra-high theoretical capacity, making them ideal for high-performance anode applications. However, the synthesis of carbyne alternating carbon-carbon triple and single bonds faces challenges due to instability of synthetic intermediates and unwanted side reactions. In this study, a smart Greedy Snake strategy was employed to synthesize Si capped alkyne rich carbon (Si-Alkyne-C) materials, which showed excellent stability and high capacity as anode electrodes. The Si-Alkyne-C materials were prepared on a copper surface through carbon-carbon coupling, with Si effectively protecting the intermediates generated during the reaction. The resulting Si-Alkyne-C exhibited a reversible capacity of up to 2776 mAh/g at a current density of 50 mA/g and an average capacity of approximately 1202 mAh/g at a high current density of 5000 mA/g for 5000 cycles, outperforming other carbon and anode materials. These findings not only provide a facile method for preparing carbyne based materials, but also open up possibilities for high-capacity anode material synthesis.