Du Xiaohang, Wen Chenxu, Luo Yuhong, Luo Dan, Yang Tingzhou, Wu Lanlan, Li Jingde, Liu Guihua, Chen Zhongwei
School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin, 300130, China.
Shandong Haihua Co., Ltd., Weifang, Shandong, 262737, China.
Small. 2023 Nov;19(47):e2304131. doi: 10.1002/smll.202304131. Epub 2023 Jul 24.
As an attractive high-energy-density technology, the practical application of lithium-sulfur (Li-S) batteries is severely limited by the notorious dissolution and shuttle effect of lithium polysulfides (LiPS), resulting in sluggish reaction kinetics and uncontrollable dendritic Li growth. Herein, a p-n typed heterostructure consisting of n-type MoS nanoflowers embedded with p-type NiO nanoparticles is designed on carbon nanofibers (denoted as NiO-MoS @CNFs) as both cathode sulfur immobilizer and anode Li stabilizer for practical Li-S batteries. Such p-n typed heterostructure is proposed to establish the built-in electric field across the heterointerface for facilitated the positive charge to reach the surface of NiO-MoS , meanwhile inherits the excellent LiPS adsorption ability of p-type NiO nanoparticles and catalytic ability of n-type MoS . As the anode matrix, the implementation of NiO-MoS heterostructure can prevent the growth of Li dendrites by enhancing the lithiophilicity and reducing local current density. The obtained Li-S full battery exhibits an ultra-high areal capacity over 7.3 mAh cm , far exceeding that of current commercial Li-ion batteries. Meanwhile, a stable cycling performance can be achieved under low electrolyte/sulfur ratio of 5.8 µL mg and negative/positive capacity ratio of 1. The corresponding pouch cell maintains high energy density of 305 Wh kg and stable cycling performance under various bending angles.
作为一种极具吸引力的高能量密度技术,锂硫(Li-S)电池的实际应用受到多硫化锂(LiPS)臭名昭著的溶解和穿梭效应的严重限制,导致反应动力学迟缓以及锂枝晶生长不可控。在此,在碳纳米纤维上设计了一种由嵌入p型NiO纳米颗粒的n型MoS纳米花组成的p-n型异质结构(表示为NiO-MoS@CNFs),作为实用Li-S电池的正极硫固定剂和负极锂稳定剂。提出这种p-n型异质结构以在异质界面上建立内建电场,便于正电荷到达NiO-MoS表面,同时继承p型NiO纳米颗粒优异的LiPS吸附能力和n型MoS的催化能力。作为负极基体,NiO-MoS异质结构的实施可以通过增强亲锂性和降低局部电流密度来防止锂枝晶的生长。所制备的Li-S全电池展现出超过7.3 mAh cm的超高面积容量,远远超过当前商用锂离子电池。同时,在低至5.8 μL mg的电解液/硫比和1的负/正容量比下可实现稳定的循环性能。相应的软包电池在各种弯曲角度下均保持305 Wh kg的高能量密度和稳定的循环性能。