Self-template synthesis of peapod-like MnO@N-doped hollow carbon nanotubes as an advanced anode for lithium-ion batteries

The exploration of low-cost and high-performance transition metal oxides/carbon (TMOs/C)–based anodes to replace commercial graphite is still a huge challenge for the development of lithium-ion batteries (LIBs). In this work, MnO@N-doped hollow carbon nanotubes (MnO@NHCNT- v , v refers to the adding volume of pyrrole) hybrids are successfully prepared by a facile self-template strategy using Mn 3 O 4 nanotubes (Mn 3 O 4 NT) and pyrrole (PY) as the precursors. The morphology, structure and composition of these MnO@NHCNT- v samples are systematically investigated. And the effect of PY adding amounts on the synthesis of MnO@NHCNT- v samples is also explored. The results show that the Mn 3 O 4 NT works as a self-template, which releases Mn 3+ and guides the growth of polypyrrole (PPY) on Mn 3 O 4 NT. Meanwhile, it is demonstrated that the synthesis of MnO@NHCNT- v hybrids can be well regulated by the added PY amounts. As a result, MnO@NHCNT-1 hybrid not only makes a good balance on the proportion of MnO and carbon matrix but also simultaneously obtains unique peapod-like structure and successful N doping in NHCNT, resulting in good electrical contact between the two components, enhanced chemical binding by Mn–N–C bonds and enough void space inside its microstructure. Benefitting from these merits, the resulting MnO@NHCNT-1 hybrid exhibits outstanding cycling stability and rate capability when used as a LIBs anode. Our work offers a good guidance on the design and preparation of low-price and high-performance TMOs/C-based LIBs anodes. Graphical abstract