Weak-Solvent-Coordination Inducing MnNCN Preferential Orientation Toward High-Capacity and Fast-Charge Lithium-Ion Storage

MnNCN with wide interlayer channels exhibits high pseudocapacitance properties, making it a potential high-capacity fast-charging anode material for Li-ion batteries. However, polycrystalline phase structure along with complex grain boundaries severely hinder ionic and electronic transport in bulk structure and also charge-transfer at interface, suppressing capacity output and rate capability. Here, we propose a solvent-coordination-induced crystal orientation strategy for controllable synthesis of preferentially oriented MnNCN with highly active crystal planes and large specific surface areas and further construct a highly integrated MnNCN/CNT composite anode for practical verifications. Systematic studies demonstrated that the weak coordination of water-based solvent facilitated MnNCN (003) facet orientation to form nano-flower-like structures. The obtained MnNCN features highly oriented (003) facet and abundant specific surface area, the integrated MnNCN/CNT electrode endows excellent electrical, chemical, and volume properties, enabling promising electrochemical performance. Notably, at a loading of 8 mg cm⁻², the electrode exhibits a high reversible capacity of 802 mAh g⁻¹ at 0.1 C, a high rate capability of 305 mAh g⁻¹ at 10 C, and a high capacity retention of 83% after 800 cycles at 1 C. MnNCN anode demonstrates a great potential for high-energy-density Li-ion batteries, LiNi_0.8Co_0.1Mn_0.1O₂//MnNCN/CNT pouch-cell exhibits a long cycle-life over 200 cycles.