A Comparative Study of Degradation Behaviors of LiFePO 4 , LiMn 2 O 4 , and LiNi 0.8 Mn 0.1 Co 0.1 O 2 in Different Aqueous Electrolytes
A Comparative Study of Degradation Behaviors of LiFePO 4 , LiMn 2 O 4 , and LiNi 0.8 Mn 0.1 Co 0.1 O 2 in Different Aqueous Electrolytes
复制标题
LiFePO 4 、LiMn 2 O 4 和LiNi 0.8 Mn 0.1 Co 0.1 O 2 在不同水电解质中降解行为的比较研究
DOI：
10.1149/1945-7111/ad24c0
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发表时间：
2024
影响因子：
3.9
通讯作者：
Lin, Feng
中科院分区：
文献类型：
--
作者：
Zhang, Yuxin;Hu, Anyang;Hou, Dong;Kwon, Gihan;Xia, Dawei;Li, Luxi;Lin, Feng
由于水电解质本身的不可燃性，水锂离子电池（ALIBs）是一类重要的化学电池。然而，水对大多数正极材料是有害的，可能导致电池快速失效。识别不同正极材料的降解机理，评价其优缺点，对于指导材料的选择和最大化其电化学性能至关重要。在本研究中，我们研究了lifepo4 (LFP), limn2o4 （LMO）和LiNi 0.8 Mn 0.1 Co 0.1 o2 （NMC）阴极在没有保护涂层的情况下，在三种不同的水电解质，即水包盐，水包盐和分子拥挤电解质中的稳定性。后两种是被广泛报道的“缺水电解质”。由于晶体结构稳定，在分子拥挤电解质中循环的LFP在对称电池和满电池中都表现出最佳的循环寿命。Mn的溶解和表面还原加速了LMO在富水电解质中的容量衰减。另一方面，整体结构的坍塌导致NMC阴极的退化。LMO在缺乏水的水溶液电解质中表现出比NMC更好的全电池性能。LFP被证明比LMO和NMC更有希望用于长周期寿命的ALIB充满电池，特别是在分子拥挤电解质中。然而，这里研究的水电解质都没有提供足够的电池性能，可以与传统的非水电解质竞争。这项工作揭示了橄榄石、尖晶石和层状阴极在不同水溶液中的降解机制，并为改进alib的电极材料和电解质提供了见解。
Aqueous Li-ion batteries (ALIBs) are an important class of battery chemistries owing to the intrinsic non-flammability of aqueous electrolytes. However, water is detrimental to most cathode materials and could result in rapid cell failure. Identifying the degradation mechanisms and evaluating the pros and cons of different cathode materials are crucial to guide the materials selection and maximize their electrochemical performance in ALIBs. In this study, we investigate the stability of LiFePO 4 (LFP), LiMn 2 O 4 (LMO) and LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC) cathodes, without protective coating, in three different aqueous electrolytes, ie, salt-in-water, water-in-salt, and molecular crowding electrolytes. The latter two are the widely reported" water-deficient electrolytes." LFP cycled in the molecular crowding electrolyte exhibits the best cycle life in both symmetric and full cells owing to the stable crystal structure. Mn dissolution and surface reduction accelerate the capacity decay of LMO in water-rich electrolyte. On the other hand, the bulk structural collapse leads to the degradation of NMC cathodes. LMO demonstrates better full-cell performance than NMC in water-deficient aqueous electrolytes. LFP is shown to be more promising than LMO and NMC for long-cycle-life ALIB full cells, especially in the molecular crowding electrolyte. However, none of the aqueous electrolytes studied here provide enough battery performance that can compete with conventional non-aqueous electrolytes. This work reveals the degradation mechanisms of olivine, spinel, and layered cathodes in different aqueous electrolytes and yields insights into improving electrode materials and electrolytes for ALIBs.