More Like this

1. Rechargeable Li/Cl 2 Battery Down to −80 °C

   https://doi.org/10.1002/adma.202307192  

   Liang, Peng ; Zhu, Guanzhou ; Huang, Cheng‐Liang ; Li, Yuan‐Yao ; Sun, Hao ; Yuan, Bin ; Wu, Shu‐Chi ; Li, Jiachen ; Wang, Feifei ; Hwang, Bing‐Joe ; et al ( December 2023 , Advanced Materials)

   Low temperature rechargeable batteries are important to life in cold climates, polar/deep‐sea expeditions, and space explorations. Here, this work reports 3.5–4 V rechargeable lithium/chlorine (Li/Cl₂) batteries operating down to −80 °C, employing Li metal negative electrode, a novel carbon dioxide (CO₂) activated porous carbon (KJCO₂) as the positive electrode, and a high ionic conductivity (≈5–20 mS cm⁻¹from −80 °C to room‐temperature) electrolyte comprised of aluminum chloride (AlCl₃), lithium chloride (LiCl), and lithium bis(fluorosulfonyl)imide (LiFSI) in low‐melting‐point (−104.5 °C) thionyl chloride (SOCl₂). Between room‐temperature and −80 °C, the Li/Cl₂battery delivers up to ≈29 100–4500 mAh g⁻¹first discharge capacity (based on carbon mass) and a 1200–5000 mAh g⁻¹reversible capacity over up to 130 charge–discharge cycles. Mass spectrometry and X‐ray photoelectron spectroscopy probe Cl₂trapped in the porous carbon upon LiCl electro‐oxidation during charging. At −80 °C, Cl₂/SCl₂/S₂Cl₂generated by electro‐oxidation in the charging step are trapped in porous KJCO₂carbon, allowing for reversible reduction to afford a high discharge voltage plateau near ≈4 V with up to ≈1000 mAh g⁻¹capacity for SCl₂/S₂Cl₂reduction and up to ≈4000 mAh g⁻¹capacity at ≈3.1 V plateau for Cl₂reduction.

    

   more » « less
2. Dual‐Solvent Li‐Ion Solvation Enables High‐Performance Li‐Metal Batteries

   https://doi.org/10.1002/adma.202008619  

   Wang, Hansen ; Yu, Zhiao ; Kong, Xian ; Huang, William ; Zhang, Zewen ; Mackanic, David G. ; Huang, Xinyi ; Qin, Jian ; Bao, Zhenan ; Cui, Yi ( May 2021 , Advanced Materials)

   Novel electrolyte designs to further enhance the lithium (Li) metal battery cyclability are highly desirable. Here, fluorinated 1,6‐dimethoxyhexane (FDMH) is designed and synthesized as the solvent molecule to promote electrolyte stability with its prolonged –CF₂– backbone. Meanwhile, 1,2‐dimethoxyethane is used as a co‐solvent to enable higher ionic conductivity and much reduced interfacial resistance. Combining the dual‐solvent system with 1mlithium bis(fluorosulfonyl)imide (LiFSI), high Li‐metal Coulombic efficiency (99.5%) and oxidative stability (6 V) are achieved. Using this electrolyte, 20 µm Li||NMC batteries are able to retain≈80% capacity after 250 cycles and Cu||NMC anode‐free pouch cells last 120 cycles with 75% capacity retention under≈2.1 µL mAh⁻¹lean electrolyte conditions. Such high performances are attributed to the anion‐derived solid‐electrolyte interphase, originating from the coordination of Li‐ions to the highly stable FDMH and multiple anions in their solvation environments. This work demonstrates a new electrolyte design strategy that enables high‐performance Li‐metal batteries with multisolvent Li‐ion solvation with rationally optimized molecular structure and ratio.

    

   more » « less
3. A Dual‐Crosslinking Design for Resilient Lithium‐Ion Conductors

   https://doi.org/10.1002/adma.201804142  

   Lopez, Jeffrey ; Sun, Yongming ; Mackanic, David G. ; Lee, Minah ; Foudeh, Amir M. ; Song, Min‐Sang ; Cui, Yi ; Bao, Zhenan ( September 2018 , Advanced Materials)

   Solid‐state electrolyte materials are attractive options for meeting the safety and performance needs of advanced lithium‐based rechargeable battery technologies because of their improved mechanical and thermal stability compared to liquid electrolytes. However, there is typically a tradeoff between mechanical and electrochemical performance. Here an elastic Li‐ion conductor with dual covalent and dynamic hydrogen bonding crosslinks is described to provide high mechanical resilience without sacrificing the room‐temperature ionic conductivity. A solid‐state lithium‐metal/LiFePO₄cell with this resilient electrolyte can operate at room temperature with a high cathode capacity of 152 mAh g⁻¹for 300 cycles and can maintain operation even after being subjected to intense mechanical impact testing. This new dual crosslinking design provides robust mechanical properties while maintaining ionic conductivity similar to state‐of‐the‐art polymer‐based electrolytes. This approach opens a route toward stable, high‐performance operation of solid‐state batteries even under extreme abuse.

    

   more » « less
4. Operando EDXRD Study of All‐Solid‐State Lithium Batteries Coupling Thioantimonate Superionic Conductors with Metal Sulfide

   https://doi.org/10.1002/aenm.202002861  

   Sun, Xiao ; Stavola, Alyssa M. ; Cao, Daxian ; Bruck, Andrea M. ; Wang, Ying ; Zhang, Yunlu ; Luan, Pengcheng ; Gallaway, Joshua W. ; Zhu, Hongli ( December 2020 , Advanced Energy Materials)

   Sulfide solid‐state electrolytes have remarkable ionic conductivity and low mechanical stiffness but suffer from relatively narrow electrochemical and chemical stability with electrodes. Therefore, pairing sulfide electrolytes with the proper cathode is crucial in developing stable all‐solid‐state Li batteries (ASLBs). Herein, one type of thioantimonate ion conductor, Li_6+xGe_xSb_1−xS₅I, with different compositions is systematically synthesized and studied, among these compositions, an outstanding ionic conductivity of 1.6 mS cm⁻¹is achieved with Li_6.6Ge_0.6Sb_0.4S₅I. To improve the energy density and advance the interface compatibility, a metal sulfide FeS₂cathode with a high theoretical capacity (894 mAh g⁻¹) and excellent compatibility with sulfide electrolytes is coupled with Li_6.6Ge_0.6Sb_0.4S₅I in ASLBs without additional interface engineering. The structural stabilities of Li_6.6Ge_0.6Sb_0.4S₅I and FeS₂during cycling are characterized by operando energy dispersive X‐ray diffraction, which allows rapid collection of structural data without redesigning or disassembling the sealed cells and risking contamination by air. The electrochemical stability is assessed, and a safe operating voltage window ranging from 0.7≈2.4 V (vs. In–Li) is confirmed. Due to the solid confinement in the ASLBs, the Fe⁰aggregation and polysulfides shuttle effects are well addressed. The ASLBs exhibit an outstanding initial capacity of 715 mAh g⁻¹at C/10 and are stable for 220 cycles with a high capacity retention of 84.5% at room temperature.

    

   more » « less
5. In situ formation of a multicomponent inorganic-rich SEI layer provides a fast charging and high specific energy Li-metal battery

   https://doi.org/10.1039/C9TA05063A  

   Sun, Ho-Hyun ; Dolocan, Andrei ; Weeks, Jason A. ; Rodriguez, Rodrigo ; Heller, Adam ; Mullins, C. Buddie ( July 2019 , Journal of Materials Chemistry A)

   The performance of the rechargeable Li metal battery anode is limited by the poor ionic conductivity and poor mechanical properties of its solid-electrolyte interphase (SEI) layer. To overcome this, a 3 : 1 v/v ethyl methyl carbonate (EMC) : fluoroethylene carbonate (FEC) containing 0.8 M lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and 0.2 M lithium difluoro(oxalate)borate (LiDFOB) dual-salts with 0.05 M lithium hexafluorophosphate (LiPF 6 ) was tested to promote the formation of a multitude of SEI-beneficial species. The resulting SEI layer was rich in LiF, Li 2 CO 3 , oligomeric and glass borates, Li 3 N, and Li 2 S, which enhanced its role as a protective yet Li + conductive film, stabilizing the lithium metal anode and minimizing dead lithium build-up. With a stable SEI, a Li/Li[Ni 0.59 Co 0.2 Mn 0.2 Al 0.01 ]O 2 Li-metal battery (LMB) retains 75% of its 177 mA h g −1 specific discharge capacity for 500 hours at a coulombic efficiency of greater than 99.3% at the fast charge–discharge rate of 1.8 mA cm −2 . 

   more » « less