A BF 3 ‐Doped MXene Dual‐Layer Interphase for a Reliable Lithium‐Metal Anode
A BF 3 ‐Doped MXene Dual‐Layer Interphase for a Reliable Lithium‐Metal Anode
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用于可靠锂金属阳极的 BF 3 — 掺杂 MXene 双层中间相
DOI：
10.1002/adma.202210111
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发表时间：
2022
影响因子：
29.4
通讯作者：
Niu, Junjie
中科院分区：
文献类型：
--
作者：
Shang, Mingwei;Shovon, Osman Goni;Wong, Francis En Yoong;Niu, Junjie
报道了由原位形成的羧酸锂有机层和Li金属上的薄的BF 3掺杂单层Ti 3C 2 MXene组成的双层界面。蜂窝结构的有机层增加了电解质的润湿性，从而形成薄的固体电解质界面（SEI）。而BF 3掺杂的单层MXene为锂的均匀成核和生长提供了丰富的活性位点，导致SEI层中富含无机成分的厚度减少约50%。在对称电池中循环1000 h后，超电势低于30 mV。功能性BF 3基团，沿着MXene优异的电子导电性和光滑的表面，大大降低了锂镀/剥脱能垒，从而实现无枝晶的锂金属阳极。以这种双层涂层锂金属作为阳极的电池显示出极大改善的电化学性能。在350次循环后，在1.0 C下实现了175.4 mAh g− 1的高容量保持率。在容量为475 mAh的软包电池中，电池仍然表现出165.6 mAh g-1的高放电容量，200次循环后的容量保持率为90.2%。与纯Li金属的快速容量衰减相反，使用NCA作为阴极的电池在纽扣电池和袋式电池中也显示出优异的容量保持率。双层改性表面提供了稳定锂金属阳极的有效方法。
A dual‐layer interphase that consists of an in‐situ‐formed lithium carboxylate organic layer and a thin BF3‐doped monolayer Ti3C2MXene on Li metal is reported. The honeycomb‐structured organic layer increases the wetting of electrolyte, leading to a thin solid electrolyte interface (SEI). While the BF3‐doped monolayer MXene provides abundant active sites for lithium homogeneous nucleation and growth, resulting in about 50% reduced thickness of inorganic‐rich components among the SEI layer. A low overpotential of less than 30 mV over 1000 h cycling in symmetric cells is received. The functional BF3groups, along with the excellent electronic conductivity and smooth surface of the MXene, greatly reduce the lithium plating/stripping energy barrier, enabling a dendrite‐free lithium‐metal anode. The battery with this dual‐layer coated lithium metal as the anode displays greatly improved electrochemical performance. A high capacity‐retention of 175.4 mAh g−1at 1.0 C is achieved after 350 cycles. In a pouch cell with a capacity of 475 mAh, the battery still exhibits a high discharge capacity of 165.6 mAh g−1with a capacity retention of 90.2% after 200 cycles. In contrast to the fast capacity decay of pure Li metal, the battery using NCA as the cathode also displays excellent capacity retention in both coin and pouch cells. The dual‐layer modified surface provides an effective approach in stabilizing the Li‐metal anode.