Yuan Zeyu, Wang Lili, Li DongDong, Cao Junming, Han Wei
Sino-Russian International Joint Laboratory for Clean Energy and Energy Conversion Technology, College of Physics, International Center of Future Science, Jilin University, Changchun 130012, People's Republic of China.
State Key Laboratory for Superlattices and Microstructures, Institution of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
ACS Nano. 2021 Apr 27;15(4):7439-7450. doi: 10.1021/acsnano.1c00849. Epub 2021 Mar 23.
Sodium-ion batteries operating at room temperature have emerged as a generation of energy storage devices to replace lithium-ion batteries; however, they are limited by a lack of anode materials with both an adequate lifespan and excellent rate capability. To address this issue, we developed NbCT MXene-framework MoS nanosheets coated with carbon (NbCT@MoS@C) and constructed a robust three-dimensional cross-linked structure. In such a design, highly conductive NbCT MXene nanosheets prevent the restacking of MoS sheets and provide efficient channels for charge transfer and diffusion. Additionally, the hierarchical carbon coating has a certain level of volume elasticity and excellent electrical conductivity to guarantee the intercalation of sodium ions, facilitating both fast kinetics and long-term stability. As a result, the NbCT@MoS@C anode delivers an ultrahigh reversible capacity of 530 mA h g at 0.1 A g after 200 cycles and very long cycling stability with a capacity of 403 mA h g and only 0.01% degradation per cycle for 2000 cycles at 1.0 A g. Moreover, this anode has an outstanding capacity retention rate of approximately 88.4% from 0.1 to 1 A g in regard to rate performance. Most importantly, the NbCT@MoS@C anode can realize a quick charge and discharge at current densities of 20 or even 40 A g with capacities of 340 and 260 mAh g, respectively, which will increase the number of practical applications for sodium-ion batteries.
室温下运行的钠离子电池已成为新一代有望取代锂离子电池的储能装置；然而，它们受到缺乏兼具足够寿命和优异倍率性能的负极材料的限制。为了解决这个问题，我们开发了一种包覆碳的NbCT MXene框架MoS纳米片（NbCT@MoS@C），并构建了一种坚固的三维交联结构。在这种设计中，高导电性的NbCT MXene纳米片可防止MoS片层的重新堆叠，并为电荷转移和扩散提供有效的通道。此外，分级碳包覆具有一定程度的体积弹性和优异的导电性，以保证钠离子的嵌入，促进快速动力学和长期稳定性。结果，NbCT@MoS@C负极在0.1 A g下循环200次后可提供530 mA h g的超高可逆容量，并且具有非常长的循环稳定性，在1.0 A g下循环2000次时容量为403 mA h g，每次循环仅降解0.01%。此外，就倍率性能而言，该负极在0.1至1 A g范围内具有约88.4%的出色容量保持率。最重要的是，NbCT@MoS@C负极在20甚至40 A g的电流密度下分别具有340和260 mAh g的容量时能够实现快速充放电，这将增加钠离子电池的实际应用数量。
