More Like this

1. A BF ₃ ‐Doped MXene Dual‐Layer Interphase for a Reliable Lithium‐Metal Anode

   https://doi.org/10.1002/adma.202210111  

   Shang, Mingwei; Shovon, Osman_Goni; Wong, Francis_En_Yoong; Niu, Junjie (December 2022, Advanced Materials)

   Abstract 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 BF₃ groups, 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. 

   more » « less
2. Solid Electrolytes for Li−S Batteries: Solid Solutions of Poly(ethylene oxide) with LixPON- and LixSiPON-Based Polymers

   https://doi.org/10.1021/acsami.0c06196  

   Temeche, E.; Zhang, X.; Laine, R. M. (June 2020, ACS applied materials interfaces)

   We report here efforts to synthesize free-standing, dry polymer electrolytes that exhibit superior ionic conductivities at ambient for Li−S batteries. Co-dissolution of poly(ethylene oxide) (PEO) (Mn 900k) with LixPON and LixSiPON polymer systems at a ratio of approximately 3:2 followed by casting provides transparent, solid-solution films 25−50 μm thick, lowering PEO crystallinity, and providing measured impedance values of 0.1−2.8 × 10−3 S/cm at ambient. These values are much higher than simple PEO/Li+ salt systems. These solid-solution polymer electrolytes (PEs) are (1) thermally stable to 100 °C; (2) offer activation energies of 0.2−0.5 eV; (3) suppress dendrite formation; and (4) enable the use of lithium anodes at current densities as high as 3.5 mAh/cm2. Galvanostatic cycling of SPAN/PEs/Li cell (SPAN = sulfurized, carbonized polyacrylonitrile) shows discharge capacities of 1000 mAh/gsulfur at 0.25C and 800 mAh/gsulfur at 1C with high coulumbic efficiency over 100 cycles. 

   more » « less
3. Enabling Uniform and Accurate Control of Cycling Pressure for All‐Solid‐State Batteries

   https://doi.org/10.1002/aenm.202304327  

   Chen, Yu‐Ting; Jang, Jihyun; Oh, Jin_An_Sam; Ham, So‐Yeon; Yang, Hedi; Lee, Dong‐Ju; Vicencio, Marta; Lee, Jeong_Beom; Tan, Darren_H_S; Chouchane, Mehdi; et al (May 2024, Advanced Energy Materials)

   Abstract All‐solid‐state batteries are emerging as potential successors in energy storage technologies due to their increased safety, stemming from replacing organic liquid electrolytes in conventional Li‐ion batteries with less flammable solid‐state electrolytes. However, all‐solid‐state batteries require precise control over cycling pressure to maintain effective interfacial contacts between materials. Traditional uniaxial cell holders, often used in battery research, face challenges in accommodating electrode volume changes, providing uniform pressure distribution, and maintaining consistent pressure over time. This study introduces isostatic pouch cell holders utilizing air as pressurizing media to achieve uniform and accurately regulated cycling pressure. LiNi_0.8Co_0.1Mn_0.1O₂| Li₆PS₅Cl | Si pouch cells are fabricated and tested under 1 to 5 MPa pressures, revealing improved electrochemical performance with higher cycling pressures, with 2 MPa as the minimum for optimal operation. A bilayer pouch cell with a theoretical capacity of 100 mAh, cycled with an isostatic pouch cell holder, demonstrated a first‐cycle Coulombic efficiency of 76.9% and a discharge capacity of 173.6 mAh g⁻¹(88.1 mAh), maintaining 83.6% capacity after 100 cycles. These findings underscore the effectiveness of isostatic pouch cell holders in enhancing the performance and practical application of all‐solid‐state batteries. 

   more » « less
4. Designing Lithiophilic Lithium Metal Surface by a Hybrid Covalent Organic Framework and MXene Coating

   https://doi.org/10.1002/smll.202501769  

   Shovon, Osman_Goni; Wong, Francis_En_Yoong; Niu, Junjie (April 2025, Small)

   Abstract With the increasing demand for developing large‐energy‐density and safe batteries, a reliable lithium metal as an anode becomes more and more important in various lithium metal and solid‐state batteries. On the basis of better lithium regulation from MXene, a lithiophilic lithium metal surface is designed by introducing a 2D hybrid coating that consists of a thin covalent organic framework (COF‐1) modified MXene layer (denoted as COF‐MXene‐Li). The abundant lithiophilic boroxine sites on 2D COF‐1 attract lithium ions while the MXene further regulates lithium homogeneous nucleation and growth, thus preventing dendrite formation. The coin cell battery paired with LiNi_0.8Mn_0.1Co_0.1O₂(NMC811) as cathode material displays 17% more capacity retention compared with pure lithium metal after 400 cycles at 0.5C.Over 81.4% capacity retention along with 99.96% Coulombic efficiency (CE) of a 1.0 Ah pouch cell versus LiNi_0.8Co_0.15Al_0.05O₂(NCA) after 250 cycles is received. The assembled 1.6 Ah pouch cell with NMC811 show an energy density of up to 366.7 Wh Kg⁻¹and an actual energy density based on the whole cell of up to 339.7 Wh Kg⁻¹. The improved cycling stability particularly in pouch cells opens broad applications for this hybrid coating modified lithium metal as anode electrode in a variety of large‐energy‐density battery systems. 

   more » « less
5. Lithium Tritelluride as an Electrolyte Additive for Stabilizing Lithium Deposition and Enhancing Sulfur Utilization in Anode‐Free Lithium–Sulfur Batteries

   https://doi.org/10.1002/adfm.202304568  

   Lai, Tianxing; Bhargav, Amruth; Manthiram, Arumugam (June 2023, Advanced Functional Materials)

   Abstract Despite the potential to become the next‐generation energy storage technology, practical lithium–sulfur (Li–S) batteries are still plagued by the poor cyclability of the lithium‐metal anode and sluggish conversion kinetics of S species. In this study, lithium tritelluride (LiTe₃), synthesized with a simple one‐step process, is introduced as a novel electrolyte additive for Li–S batteries. LiTe₃quickly reacts with lithium polysulfides and functions as a redox mediator to greatly improve the cathode kinetics and the utilization of active materials in the cathode. Moreover, the formation of a Li₂TeS₃/Li₂Te‐enriched interphase layer on the anode surface enhances ionic transport and stabilizes Li deposition. By regulating the chemistry on both the anode and cathode sides, this additive enables a stable operation of anode‐free Li–S batteries with only 0.1 mconcentration in conventional ether‐based electrolytes. The cell with the LiTe₃additive retains 71% of the initial capacity after 100 cycles, while the control cell retains only 23%. More importantly, with high utilization of Te, the additive enables significantly better cyclability of anode‐free pouch full‐cells under lean electrolyte conditions. 

   more » « less