Abstract TMDC have a unique layered structure that allows the insertion or extraction of various guest substances between layers, making them advantageous in energy storage. In this article, we demonstrate a sodium-intercalated electrode based on nanoflower 1T–2H MoSe2–graphene with an ultrahigh electrochemical performance for highly efficient energy storage applications. To increase the probability that ion insertion/extraction reactions occur inside the electrode material, we insert sodium ions into MoSe2–graphene material using a simple one-step hydrothermal method. Through density functional theory, we find that the insertion of sodium ions not only expands the distance between the layers to provide space for electrolyte ions but also moves the Fermi level closer to the conduction band, increasing the conductivity of MoSe2. The nanoflower structure provides a large specific surface area and increases the contact of ions with the surface of the material. The composite electrode has an ultrahigh capacity of 143.6 mAh g−1 at a current density of 0.5 A g−1. The all-solid-state supercapacitor makes with the composite electrode exhibits a superhigh power density of up to 3024 W kg−1.This study achieves an enhanced and efficient energy storage in a simple and direct way.

中文翻译：

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钠离子插层纳米花1T-2H MoSe2-石墨烯纳米复合材料作为全固态超级电容器的电极

摘要 TMDC 具有独特的层状结构，允许层间插入或提取各种客体物质，使其在储能方面具有优势。在本文中，我们展示了一种基于纳米花 1T-2H MoSe2-石墨烯的插钠电极，具有超高的电化学性能，可用于高效储能应用。为了增加在电极材料内部发生离子嵌入/脱出反应的可能性，我们使用简单的一步水热法将钠离子插入到 MoSe2-石墨烯材料中。通过密度泛函理论，我们发现钠离子的插入不仅扩大了层之间的距离，为电解质离子提供了空间，而且使费米能级更接近导带，增加了 MoSe2 的电导率。纳米花结构提供了大的比表面积并增加了离子与材料表面的接触。该复合电极在0.5 A g-1的电流密度下具有143.6 mAh g-1的超高容量。使用复合电极制成的全固态超级电容器具有高达 3024 W kg-1 的超高功率密度。该研究以简单直接的方式实现了增强和高效的能量存储。