Based on the existing calculation reports, sulfur doping is an effective approach to alleviate the structure collapse of Li₂MnSiO₄ during cycling. Herein, we investigate the feasibility and limitations of S doping in Li₂MnSiO₄ by experiment. In our work, the solid solubility of S is confirmed and exceeding the threshold results in MnS impurity. The existence state and site of the S element in a Li₂MnSiO₄ crystal structure is also confirmed. It is found that S doping significantly improves the structural reversibility and cycling stability. Compared with a pristine sample, a 1mol% S doped sample exhibits a much higher initial coulombic efficiency (88.3%), excellent capacity retention (98% at 10^th cycles for instance) and enhanced rate performance. Moreover, the 1mol% S doped sample can retain a discharge capacity of 137 mA h g⁻¹ after 30 cycles while the pristine sample only has 61.6 mA h g⁻¹. This study confirms the effectivity of S doping in suppressing the structural distortion in Li₂MnSiO₄.

中文翻译：

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硫掺杂对Li ₂ MnSiO ₄正极材料的结构可逆性和循环稳定性的影响†

根据现有的计算报告，硫掺杂是减轻循环过程中Li ₂ MnSiO ₄的结构塌陷的有效方法。在这里，我们通过实验研究了在Li ₂ MnSiO _4中掺杂S的可行性和局限性。在我们的工作中，证实了S的固溶性，并且超过阈值会导致MnS杂质。Li ₂ MnSiO _4中S元素的存在状态和位置晶体结构也得到证实。发现S掺杂显着改善了结构可逆性和循环稳定性。与原始样品相比，掺杂1mol％S的样品表现出更高的初始库仑效率（88.3％），出色的容量保持率（例如，在^第10^个循环时为98％）和更高的速率性能。此外，在30个循环之后，掺杂有1mol％S的样品可以保持137mA hg ^-1的放电容量，而原始样品仅具有61.6mA hg ^-1。该研究证实了S掺杂对抑制Li ₂ MnSiO _4中的结构变形的有效性。