Abstract：
Hard carbon anode demonstrates exceptional potential in sodium-ion batteries due to their cost-effectivenss and superior plateau capacity. However, the proximity of the plateau capacity to the cut-off voltage of battery operation and the premature cut-off voltage response caused by polarization at high rates greatly limit the exploitation of plateau capacities, raising big concerns about inferior rate performance of high-plateau-capacity hard carbon. In this work, a facile pre-oxidation strategy is proposed for fabricating lignin-derived hard carbon. Both high-plateau capacity and sodiation kinetics are significantly enhanced due to the introduction of expanded pseudo-graphitic domains and high-speed closed pores. Impressively, the optimized hard carbon exhibits an increased reversible capacity from 252.1 to 302.0 mAh g-1, alongside superior rate performance (174.7 mAh g-1 at 5 C) and stable cyclability over 500 cycles. This study paves a low-cost and effective pathway to modulate the microstructure of biomass-derived hard carbon materials for facilitating plateau sodium storage kinetics.
摘要：
由于硬碳阳极具有成本效益和出色的平台容量，因此在钠离子电池中具有出色的潜力。然而,高原容量与电池操作的截止电压的接近以及由高速率极化引起的过早截止电压响应极大地限制了高原容量的开发，引起了人们对高高原容量硬碳的低率性能的极大关注。在这项工作中,提出了一种简单的预氧化策略来制造木质素衍生的硬碳。由于引入了膨胀的假石墨域和高速闭孔，高平台容量和碱化动力学均显着增强。令人印象深刻的是,优化的硬碳表现出增加的可逆容量从252.1到302.0mAhg-1，以及优异的倍率性能（174.7mAhg-1在5C）和稳定的循环能力超过500次循环。这项研究为调节生物质衍生的硬碳材料的微观结构以促进平台钠储存动力学铺平了一条低成本且有效的途径。
