Stable Conversion Chemistry‐Based Lithium Metal Batteries Enabled by Hierarchical Multifunctional Polymer Electrolytes with Near‐Single Ion Conduction

Abstract

The low Coulombic efficiency and serious safety issues resulting from uncontrollable dendrite growth have severely impeded the practical applications of lithium (Li) metal anodes. Herein we report a stable quasi‐solid‐state Li metal battery by employing a hierarchical multifunctional polymer electrolyte (HMPE). This hybrid electrolyte was fabricated via in situ copolymerizing lithium 1‐[3‐(methacryloyloxy)propylsulfonyl]‐1‐(trifluoromethanesulfonyl)imide (LiMTFSI) and pentaerythritol tetraacrylate (PETEA) monomers in traditional liquid electrolyte, which is absorbed in a poly(3,3‐dimethylacrylic acid lithium) (PDAALi)‐coated glass fiber membrane. The well‐designed HMPE simultaneously exhibits high ionic conductivity (2.24×10−3 S cm−1 at 25 °C), near‐single ion conducting behavior (Li ion transference number of 0.75), good mechanical strength and remarkable suppression for Li dendrite growth. More intriguingly, the cation permselective HMPE efficiently prevents the migration of negatively charged iodine (I) species, which provides the as‐developed Li‐I batteries with high capacity and long cycling stability.

Self-templated synthesis of uniform hollow spheres based on highly conjugated three-dimensional covalent organic frameworks

“…2 , 3D-Sp-COF is prone to transport ions (such as Li + ) more efficiently. As predicted, the lithium-ion transference number ( t + ) of 3D-Sp-COF of 0.7 is recorded (Supplementary Table 1 ), which overwhelms most typical polyethylene oxide (PEO)-based polymer electrolytes 54 , 55 and even comparable to the signal-ion electrolyte systems 56 – 58 . According to the results, ion conduction pathways provided by 3D COFs play a positive role on improving the ion transport.…”

Small Groups, Big Impact: Eliminating Li+ Traps in Single-Ion Conducting Polymer Electrolytes

“…The resulting polymer electrolytes may be fabricated as solid electrolytes (often utilizing polyethylene oxide [PEO] as blend partner) ( Meziane et al., 2011 ; Ma et al., 2016 ) or “quasi-solid” electrolytes, in which substantially enhanced ionic conductivities are achieved upon addition of limited amounts (below 150 wt %) of salt-free, low-molecular-weight plasticizer(s) ( Van Schalkwijk and Scrosati, 2002 ; Rohan et al., 2015 ; Long et al., 2016 ; Cheng et al., 2018 ; Jia et al., 2018a ; Jia et al., 2018b ). This is in contrast to gel-type polymer electrolytes that might incorporate up to 2,200 wt % of plasticizer(s) ( Zhang et al., 2018 ; Zhong et al., 2019 ; Zhou et al., 2019 ). To date, merely a few quasi-solid SIPEs with a room temperature (RT) ionic conductivity of 1 mS cm −1 or higher are reported ( Deng et al., 2017 ; Oh et al., 2016 ; Rohan et al., 2014 ), whereas other plasticized SIPE material classes including block copolymers( Nguyen et al., 2018 ) or blend-type compounds( Zhang et al., 2014a ; Sun et al., 2014 ; Zhang et al., 2014b ; Qin et al., 2015 ; Rohan et al., 2015 ; Liu et al., 2016 ; Pan et al., 2016 ; Zhang et al., 2017a , 2017b ; Dong et al., 2018 ; Li et al., 2018 ; Chen et al., 2018 ; Li et al., 2019 ) do not accomplish ionic conductivities of more than 1 mS cm −1 .…”

Influence of AlPO4 Impurity on the Electrochemical Properties of NASICON‐Type Li1.5Al0.5Ti1.5(PO4)3 Solid Electrolyte

“…The use of a solid electrolyte represents an alternative because it acts as a physical barrier to prevent short circuits and increase the battery's energy density (in lithium metal batteries). In the recent years, a wide range of new solid electrolytes based on polymer, [4] ceramic, [5] or hybrid polymerceramic [6] materials have been proposed in the literature. Among ceramic electrolytes, NASICON structured phosphate [7,8] based electrolytes Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 (LAGP) [9,10] and Li 1.5 Al 0.5 Ti 1.5 (PO 4 ) 3 (LATP) [11] have garnered much attention.…”