High-Rate Long Cycle-Life Li-Air Battery Aided by Bifunctional InX3 (X = I and Br) Redox Mediators
High-Rate Long Cycle-Life Li-Air Battery Aided by Bifunctional InX3 (X = I and Br) Redox Mediators
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DOI：
10.1021/acsami.0c15200
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发表时间：
2021-01-22
影响因子：
9.5
通讯作者：
Salehi-Khojin, Amin
中科院分区：
文献类型：
--
作者：
Rastegar, Sina;Hemmat, Zahra;Salehi-Khojin, Amin
氧化还原介质（RMs）是一种基于溶液的添加剂，被广泛用于降低充电电位和提高锂氧（Li-O-2）电池的能量效率。然而，在rm存在的情况下，实现Li-O-2电池在高电流速率下的长循环寿命运行仍然是一个主要挑战。在这项研究中，我们发现了InX3 （X = I和Br）双功能RMs，二硫化钼（MoS2）纳米片作为空气电极，二甲亚砜/离子液体混合电解质和LiTFSI作为盐之间的新型协同作用，以实现Li-O-2电池在干燥空气环境下高充放电速率的长循环寿命操作。我们的研究结果表明，含InI3的电池在0.5 a g（-1）电流密度下可运行450次循环，在1 a h g（-1）固定容量下可运行217次循环，电流密度为1 g（-1）。使用InBr3的电池在电流密度为1a g（-1）的情况下可运行600次循环。这些电池也可以在2g（-1）的更高充电率下工作，最多可充电200次（用于InBr3）和160次（用于InI3）。我们的实验和计算结果表明，虽然X-3（-）是氧化还原介质的来源，LiX在MoS2阴极，In3+在锂阳极侧反应形成表面保护层，从而在干燥空气环境中充当有效的双功能RM。这一证据表明，在干燥空气环境中，电池的电流速率和循环寿命同时得到改善，为先进储能系统的研究开辟了新的方向。
Redox mediators (RMs) are solution-based additives that have been extensively used to reduce the charge potential and increase the energy efficiency of Li-oxygen (Li-O-2) batteries. However, in the presence of RMs, achieving a long cycle-life operation of Li-O-2 batteries at a high current rate is still a major challenge. In this study, we discover a novel synergy among InX3 (X = I and Br) bifunctional RMs, molybdenum disulfide (MoS2) nanoflakes as the air electrode, dimethyl sulfoxide/ionic liquid hybrid electrolyte, and LiTFSI as a salt to achieve long cycle-life operations of Li-O-2 batteries in a dry air environment at high charge-discharge rates. Our results indicate that batteries with InI3 operate up to 450 cycles with a current density of 0.5 A g(-1) and 217 cycles with a current density of 1 A g(-1) at a fixed capacity of 1 A h g(-1). Batteries with InBr3 operate up to 600 cycles with a current density of 1 A g(-1). These batteries can also operate at a higher charge rate of 2 A g(-1) up to 200 cycles (for InBr3) and 160 cycles (for InI3). Our experimental and computational results reveal that while X-3(-) is the source of the redox mediator, LiX at the MoS2 cathode, In3+ reacts on the lithium anode side to form a protective layer on the surface, thus acting as an effective bifunctional RM in a dry air environment. This evidence for a simultaneous improvement in the current rates and cycle life of a battery in a dry air atmosphere opens a new direction for research for advanced energy storage systems.