Extremely Small Pyrrhotite Fe7S8 Nanocrystals with Simultaneous Carbon‐Encapsulation for High‐Performance Na–Ion Batteries,Small

当前位置： X-MOL 学术 › Small › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Extremely Small Pyrrhotite Fe7S8 Nanocrystals with Simultaneous Carbon‐Encapsulation for High‐Performance Na–Ion Batteries
Small ( IF 13.0 ) Pub Date : 2017-11-24 , DOI: 10.1002/smll.201702816
Min-Jae Choi ₁ , Jongsoon Kim ₂ , Jung-Keun Yoo ₃ , Soonmin Yim ₁ , Jaebeom Jeon ₁ , Yeon Sik Jung ₁

Affiliation

Na/FeS_x batteries have remarkable potential applicability due to their high theoretical capacity and cost‐effectiveness. However, realization of high power‐capability and long‐term cyclability remains a major challenge. Herein, ultrafine Fe₇S₈@C nanocrystals (NCs) as a promising anode material for a Na–ion battery that addresses the above two issues simultaneously is reported. An Fe₇S₈ core with quantum size (≈10 nm) overcomes the kinetic and thermodynamic constraints of the Na‐S conversion reaction. In addition, the high degree of interconnection through carbon shells improves the electronic transport along the structure. As a result, the Fe₇S₈@C NCs electrode achieves excellent power capability of 550 mA h g⁻¹ (≈79% retention of its theoretical capacity) at a current rate of 2700 mA g⁻¹. Furthermore, a conformal carbon shell acts as a buffer layer to prevent severe volume change, which provides outstanding cyclability of ≈447 mA h g⁻¹ after 1000 cycles (≈71% retention of the initial charge capacity).

中文翻译：

极小的硅镁铁矿Fe7S8纳米晶体，具有同时碳包封的高性能钠离子电池

Na / FeS _x电池具有较高的理论容量和成本效益，因此具有巨大的潜在适用性。但是，实现高功率能力和长期可循环性仍然是一个重大挑战。在本文中，报道了超细的Fe ₇ S ₈ @C纳米晶体（NCs）作为一种有前途的Na-离子电池阳极材料，可以同时解决上述两个问题。具有量子尺寸（≈10nm）的Fe ₇ S ₈核克服了Na-S转化反应的动力学和热力学约束。另外，通过碳壳的高度互连改善了沿结构的电子传输。结果，Fe ₇ S ₈@C NCs电极在2700 mA g ^-1的电流速率下实现了550 mA hg ^-1的出色功率能力（保持其理论容量的≈79％）。此外，共形的碳壳充当缓冲层以防止剧烈的体积变化，这在1000次循环后提供了约447 mA hg ^-1的出色循环能力（保留了初始充电容量的71％）。

更新日期：2017-11-24

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南