Mo<sub>3</sub>Nb<sub>14</sub>O<sub>44</sub>: A New Li<sup>+</sup> Container for High‐Performance Electrochemical Energy Storage
Renjie Li, Guisheng Liang, Xiangzhen Zhu, Qingfeng Fu, Yongjun Chen, Lijie Luo, Chunfu Lin
Abstract
Intercalating Nb‐based oxides are promising anode compounds for lithium‐ion batteries since they have both good safety and large capacities. However, the research in this field is still limited. Here, Mo 3 Nb 14 O 44 with a large theoretical capacity of 398 mAh g –1 (Mo 6+ ↔Mo 4+ and Nb 5+ ↔Nb 3+ ) is exploited as a new Nb‐based oxide anode compound, and Mo 3 Nb 14 O 44 micron‐sized particles (Mo 3 Nb 14 O 44 ‐M) and Mo 3 Nb 14 O 44 nanowires (Mo 3 Nb 14 O 44 ‐N) are demonstrated. Mo 3 Nb 14 O 44 owns a tetragonal shear ReO 3 crystal structure (high‐symmetric space group) constructed by 4 × 4×∞ (Mo,Nb)O 6 octahedron blocks linked by MoO 4 tetrahedra, forming an A–B–A layered structure with a large interlayer spacing. This interesting structure allows fast Li + storage within the interlayers and significant intercalation‐pseudocapacitive behavior, leading to the high rate performance of Mo 3 Nb 14 O 44 ‐M/Mo 3 Nb 14 O 44 ‐N with a large 10C versus 0.1C capacity retention percentage of 38.1/54.2%. Mo 3 Nb 14 O 44 ‐M/Mo 3 Nb 14 O 44 ‐N further exhibits a safe operating potential of 1.72/1.68 V, large reversible capacity of 323/321 mAh g –1 at 0.1C, high initial coulombic efficiency of 92.2/90.0%, and good cycling stability with 71.8/75.8% capacity retention after 1000 cycles at 10C. Additionally, a LiMn 2 O 4 /Mo 3 Nb 14 O 44 ‐N full cell also performs well. Therefore, Mo 3 Nb 14 O 44 holds great promise as a fast‐charging, safe, large‐capacity, high‐efficient, and long‐life Li + anode container.