Control over porosity and crystal orientation is a huge challenge in the field of materials science. Cathode materials with high porosity and reactivity of exposed crystal planes contribute to the charge transfer kinetics, structural stability and interfacial compatibility between electrode and electrolyte. In this paper, hierarchically porous urchin-like LiNi_0.5Mn_1.5O₄ hollow spheres comprising aggregated nanosheets with highly exposed {111} facets have been successfully synthesized with ultrathin MnO₂ nanosheets encapsulating poly styrene spheres as precursor. Transmission electron microscopy results present the crystal orientation of target cathode material is exposed with dominant {111} facets, which could effectively relieve the dissolution of manganese from the lattice, thus leading to an excellent cycling stability. The charge-discharge characterizations demonstrate that the resultant urchin-like LiNi_0.5Mn_1.5O₄ hollow spheres exhibits excellent rate capability and high-rate cyclic stability. Notably, even at a high rate of 30 C, the battery can deliver about 92% of the initial discharge capacity retention after 1500 cycles. Experiment results and theoretical calculation indicate that the superior performance of the synthesized product can be ascribed to its intrinsic structure and preferred orientation growth of {111} facets. Therefore, hierarchically porous urchin-like LiNi_0.5Mn_1.5O₄ with highly exposed {111} plane is a promising cathode material for high-energy density lithium-ion batteries.

在材料科学领域，控制孔隙率和晶体取向是一项巨大的挑战。具有高孔隙率和暴露晶面反应性的阴极材料有助于电荷转移动力学，结构稳定性以及电极和电解质之间的界面相容性。本文成功地用超薄MnO ₂合成了层状多孔的Urchin状LiNi _0.5 Mn _1.5 O ₄中空球体，该球体包含具有高度暴露的{111}面的聚集纳米片。纳米片封装聚苯乙烯球体作为前体。透射电子显微镜结果表明目标阴极材料的晶体取向暴露在主要的{111}面中，这可以有效地缓解锰从晶格中的溶解，从而导致出色的循环稳定性。充放电特性表明，所得的野孩子状LiNi _0.5 Mn _1.5 O ₄中空球具有出色的速率能力和高速率循环稳定性。值得注意的是，即使在30 C的高温下，电池在1500次循环后仍可提供约92％的初始放电容量保持率。实验结果和理论计算表明，合成产物的优越性能可归因于其固有结构和{111}面的优选取向生长。因此，具有高度暴露的{111}面的分层多孔的，类似海胆的LiNi _0.5 Mn _1.5 O ₄是用于高能量密度锂离子电池的有希望的阴极材料。