碳酸鹽電解質中先進鋰金屬電池的富無機固體電解質界面相
作者:
小柯機器人發布時間:2020/11/14 16:35:35
美國馬裡蘭大學化學和生物分子Chunsheng Wang團隊設計了一種碳酸鹽電解質中先進鋰金屬電池的富無機固體電解質界面相。 該研究成果發表在2020年11月09日出版的《德國應用化學》。
在碳酸鹽巖電解質中,鋰(Li)金屬陽極表面形成的有機-無機固體電解質界面相(SEI)與Li緊密結合,並經歷與Li相同的體積變化,在沉積/溶出循環過程中會發生連續的開裂/再生。
在該文中,研究人員在鋰金屬表面設計中了一種富含無機物的SEI,通過在二甲基亞碸(DMSO)中溶解4M濃度的LiNO3作為基於碳酸氟乙烯(FEC)的電解質的添加劑來降低其與Li金屬的結合能。由於NO3-的聚集結構及其參與了初始Li+溶劑化鞘層,因此在生成的SEI中富含Li2O、Li3N和LixOy顆粒。此外,由於PF6-的還原,形成了均勻分布的LiF。富含無機物的SEI與Li的弱鍵合(高界面能)能有效地促進Li沿SEI/Li界面的擴散,阻止Li枝晶穿過SEI。因此,研究人員設計的碳酸鹽電解液可使鋰陽極獲得99.55%的高鋰沉積/溶出CE(1 mA cm-2,1.0 mAh cm‐2)。同時,電解液也使Li | LiNi 0.8 Co 0.1 Mn 0.1 O 2(NMC811)全電池(2.5 mAh cm‐2)在200次循環後仍能保持75%的初始容量,突出的CE為99.83%。
該文提出的策略為進一步優化鋰離子電池用碳酸鹽電解液提供了一種實用的解決方案。
附:英文原文
Title: Inorganic‐rich Solid Electrolyte Interphase for Advanced Lithium Metal Batteries in Carbonate Electrolytes
Author: Sufu Liu, Xiao Ji, Nan Piao, Ji Chen, Nico Eidson, Jijian Xu, Pengfei Wang, Long Chen, Jiaxun Zhang, Tao Deng, Singyuk Hou, Ting Jin, Hongli Wan, Jingru Li, Jiangping Tu, Chunsheng Wang
Issue&Volume: 09 November 2020
Abstract: In carbonate electrolytes, the organic‐inorganic solid electrolyte interphase (SEI) formed on the lithium (Li) metal anode surface is strongly bonded to Li and experiences the same volume change as Li, thus it undergoes continuous cracking/reformation during plating/stripping cycles. Here, an inorganic‐rich SEI is designed on a Li metal surface to reduce its bonding energy with Li metal by dissolving 4 M concentrated LiNO 3 in dimethyl sulfoxide (DMSO) as an additive for a fluoroethylene carbonate (FEC) based electrolyte. Due to the aggregate structure of NO 3 ‐ ions and its participation in the primary Li + solvation sheath, abundant Li 2 O, Li 3 N, and LiN x O y grains are formed in the resulting SEI, in addition to the uniform LiF distribution from the reduction of PF 6 ‐ ions. The inorganic‐rich SEI’s weak bonding (high interface energy) to Li can effectively promote Li diffusion along the SEI/Li interface and prevent Li dendrite penetration into the SEI. As a result, our designed carbonate electrolyte enables a Li anode to achieve a high Li plating/stripping CE of 99.55% (1 mA cm ‐2 , 1.0 mAh cm ‐2 ) and the electrolyte also enables a Li||LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NMC811) full cell (2.5 mAh cm‐2) to retain 75% of its initial capacity after 200 cycles with an outstanding CE of 99.83%. The concentrated additive strategy presented here provides a drop‐in practical solution to further optimize carbonate electrolytes for beyond Li‐ion batteries.
DOI: 10.1002/anie.202012005
Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202012005