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Manganese oxides with versatile valence display an enormous potential in lithium-ion battery (LIB) anode materials, but deficient lithium storage capacity, short discharge platform, and inferior cycle stability at high current density greatly hinder their application. Herein, MnO/Mn 2 O 3 nanowires coated by porous N-doped carbon (MnO/Mn 2 O 3 −NC) layers are fabricated via wrapping ZIF-8 on MnO 2 combined with annealing postprocessing. In the LIB test, this material exhibits superior initial discharge specific capability (1429.4 mAh g −1 at 0.1 A g −1 ) and improved rate performance retention of 65% (10-fold amplification from 0.5 to 5 A g −1 ). Particularly, up to an ultrahigh current density of 10 A g −1 , this anode material also possesses great cycling stability of 87% after 10 000 cycles (merely 0.0013% capacity decay per cycle), which is the best among the reported values for Mn-based compounds. On the basis of experiment data and density functional theory (DFT) calculations, the superior stability for the MnO/Mn 2 O 3 −NC anode is mainly attributed to the mutual support characteristics of heterojunction synergy, thus avoiding damage and vice versa during the energy storage process. Generally, our work proposes a special nanostructure with heterojunction synergy to ameliorate the cycling stability and rate performance of manganese-based materials.

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requires huge and expensive infrastructures to bear the harsh operating conditions, which further raises the production cost. [5] Thus, the development of energy efficient and environmental-friendly technologies for NH 3 synthesis is urgently important. Electrochemical methods powered by renewable electricity offer economical and environmentally friendly routes to produce NH 3 at room temperature. [6] Recently, electrochemical N 2 reduction reaction (NRR) under ambient conditions has been considered as a clean energy route for NH 3 production. [7] However, current NRR processes are still very inefficient, because of the extremely stable NN triple bond in N 2 (941 kJ mol −1 ), limited solubility of N 2 in the aqueous solution, and competing hydrogen evolution reaction (HER) in the aqueous electrolyte. [8] Thus, the practical application of NRR for NH 3 synthesis still has a long way to go. Recently, electrochemical nitrate (NO 3 − ) reduction reaction (NitRR) under ambient conditions has emerged as a highly promising strategy toward green NH 3 synthesis because the dissociation energy of N = O in NO 3 − (204 kJ mol −1 ) is much lower than that of the NN bond, which achieves much higher reaction rate for NH 3 production. [9] In addition, NO 3 −

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