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

ABSTRACT

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 _0.8 Co _0.1 Mn _0.1 O ₂ //MnNCN/CNT pouch‐cell exhibits a long cycle‐life over 200 cycles.