Chen He, Sun Ning, Zhu Qizhen, Soomro Razium Ali, Xu Bin
State Key Laboratory of Organic-Inorganic Composites, Beijing Key Laboratory of Electrochemical Process and Technology for Materials, Beijing University of Chemical Technology, Beijing, 100029, China.
Adv Sci (Weinh). 2022 Jul;9(20):e2200023. doi: 10.1002/advs.202200023. Epub 2022 May 4.
Sodium-ion batteries (SIBs) are regarded as a kind of promising candidate for large-scale energy storage technology. The development of advanced carbon anodes with high Na-storage capacity and initial Coulombic efficiency (ICE) from low cost, resources abundant precursors is critical for SIBs. Here, a carbon microcrystalline hybridization route to synthesize hard carbons with extensive pseudo-graphitic regions from lignite coal with the assistance of sucrose is proposed. Employing the cross-linked interaction between sucrose and lignite coal to generate carbon-based hybrid microcrystalline states, the obtained hard carbons possess pseudo-graphitic dominant phases with large interlayer spaces that facilitate Na ion's storage and transportation, as well as fewer surface defects that guarantee high ICE. The LCS-73 with an optimum cross-link demonstrates the highest Na-storage capacity of 356 mAh g and an ICE of 82.9%. The corresponding full-cell delivers a high energy density of 240 Wh kg (based on the mass of anode and cathode materials) and excellent rate capability of 106 mAh g at 10 C in addition to outstanding cycle performance with 80% retention over 500 cycles at 2 C. The proposed work offers an efficient route to develop high-performance, low-cost carbon-based anode materials with potential application for advanced SIBs.
钠离子电池（SIBs）被视为大规模储能技术的一种有前景的候选者。从低成本、资源丰富的前驱体开发具有高储钠容量和初始库仑效率（ICE）的先进碳负极对于钠离子电池至关重要。在此，提出了一种碳微晶杂化路线，借助蔗糖从褐煤合成具有广泛准石墨区域的硬碳。利用蔗糖与褐煤之间的交联相互作用产生碳基混合微晶态，所获得的硬碳具有准石墨主导相，层间距大，有利于钠离子的存储和运输，以及较少的表面缺陷，确保了高初始库仑效率。具有最佳交联的LCS-73表现出最高356 mAh g的储钠容量和82.9%的初始库仑效率。相应的全电池除了在2 C下500次循环具有80%的保持率的出色循环性能外，还在10 C下具有240 Wh kg的高能量密度（基于阳极和阴极材料的质量）以及106 mAh g的出色倍率性能。所提出的工作为开发具有高性能、低成本且有潜力应用于先进钠离子电池的碳基负极材料提供了一条有效途径。
