Constructing stable lithium metal anodes using a lithium adsorbent with a high Mn3+/Mn4+ ratio

Lithium (Li) metal batteries (LMBs) have emerged as the most prospective candidates for post-Li-ion batteries. However, the practical deployment of LMBs is frustrated by the notorious Li dendrite growth on hostless Li metal anodes. Herein, a protonated Li manganese (Mn) oxide with a high Mn3+/Mn4+ ratio is used as a Li adsorbent for constructing highly stable Li metal anodes. In addition to the Mn3+ sites with high Li affinity that afford an ultralow Li nucleation overpotential, the decrease in the average Mnn+ oxidation state also induces a disordered adsorbent structure via the Jahn-Teller effect, resulting in improved Li transfer kinetics with a significantly reduced Li electroplating overpotential. Based on the mutually improved Li diffusion and adsorption kinetics, the Li adsorbent is used as a versatile host to enable dendrite-free and stable Li metal anodes in LMBs. Consequently, a modified Li||LiNi0.8Mn0.1Co0.1O2 (NMC811) coin cell with a high NMC811 loading of 4.3 mAh cm-2 delivers a high Coulombic efficiency of 99.85% over 200 cycles and the modified Li||NMC811 pouch cell also achieves a remarkable improvement in electrochemical performance. This work demonstrates a novel approach for the preparation of highly efficient Li protection structures for safe LMBs with long lifespans

NiS Nanorods as Cathode Materials for All-Solid-State Lithium Batteries with Excellent Rate Capability and Cycling Stability

Rate capability and cycling stability are the great challenges of all-solid-state lithium batteries, owing to the low lithium ion transfer kinetics in solid materials and poor interfacial compatibility between electrodes and electrolytes. In this work, one-dimensional nanostructured NiS and lithium metal are firstly employed in Li/70% Li2S-29% P2O5-1% P2O5/Li10GeP2S12/NiS all-solid-state lithium batteries, exhibiting excellent rate capability and cycling stability. NiS nanorods, with a diameter of 20-50 nm and length of 2-3 mu m, are prepared in a controllable manner by using a solvothermal method. Electrochemical performance measurements show that the reversible discharge ca-pacities of NiS nanorod electrodes can be as high as 670, 401, and 299 mAhg(-1) at the current densities of 100, 250, and 500 mAg(-1), respectively. Also, it displays excellent cycling stability, showing reversible discharge capacities up to 338 and 243 mAhg(-1) after 100 cycles at current densities of 250 and 500 mAg(-1), respectively. The electrochemical reaction mechanism of the NiS nanorods in all-solid-state lithium batteries is revealed by combining cyclic voltammetry and ex situ XRD measurements in detail, showing a reversible conversion reaction that is almost identical with that in the traditional lithium-ion batteries that utilize liquid electrolytes

Lithium/Sulfide All-Solid-State Batteries using Sulfide Electrolytes

All-solid-state lithium batteries (ASSLBs) are considered as the next generation electrochemical energy storage devices because of their high safety and energy density, simple packaging, and wide operable temperature range. The critical component in ASSLBs is the solid-state electrolyte. Among all solid-state electrolytes, the sulfide electrolytes have the highest ionic conductivity and favorable interface compatibility with sulfur-based cathodes. The ionic conductivity of sulfide electrolytes is comparable with or even higher than that of the commercial organic liquid electrolytes. However, several critical challenges for sulfide electrolytes still remain to be solved, including their narrow electrochemical stability window, the unstable interface between the electrolyte and the electrodes, as well as lithium dendrite formation in the electrolytes. Herein, the emerging sulfide electrolytes and preparation methods are reviewed. In particular, the required properties of the sulfide electrolytes, such as the electrochemical stabilities of the electrolytes and the compatible electrode/electrolyte interfaces are highlighted. The opportunities for sulfide-based ASSLBs are also discussed

Synthesis and electrochemical properties of LiNi1/3Co1/3Mn1/3O2 cathodes in lithium-ion and all-solid-state lithium batteries

LiNi1/3Co1/3Mn1/3O2 cathodes have been prepared by a solid-state reaction process. The effects of calcination and post-annealing temperature on electrochemical performances were systematically investigated for both of the lithium-ion batteries with liquid electrolytes and all-solid-state lithium batteries with sulfide solid electrolytes. The particle size of the LiNi1/3Co1/3Mn1/3O2 materials increases with calcination temperatures, whereas after calcination, the shape and size of LiNi1/3Co1/3Mn1/3O2 particles were independent of post-annealing temperatures. The LiNi1/3Co1/3Mn1/3O2 calcinated at 850 A degrees C and followed by post-annealing at 800 A degrees C maintains 97.6 % capacity retention after 30 cycles and has a capacity of 117 mAh g(-1) at a current of 5 C (current density of 24.1 mA/cm(2)) in a voltage range of 2.8 and 4.3 V in lithium-ion batteries. Moreover, the optimal sample has the first discharge capacity of about 115 mAh g(-1) at a current density of 0.11 mA cm(-2) in the all-solid-state lithium battery with Li10GeP2S12 as solid state electrolyte. Electrochemical impedance spectroscopy measurements show that the post-annealing process plays an important role in suppressing the increase of cell impedance during charging-discharging. The experimental results suggest that the post-annealed LiNi1/3Co1/3Mn1/3O2 material is very suitable as one of the leading cathode materials for lithium-ion and solid-state lithium batteries with long cycle life and high power density

Preparation and electrochemical performances of high voltage nanosized Al_2O_3 coating LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2

A layer of nano Al_2O_3 was coated on the surface of LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 particles by sol-gel method, so the cycle performance and rate capability of LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 at a high cut-off voltage are enhanced. The structure and morphology of the materials were characterized by XRD, SEM and TEM. The electrochemical performances of the high voltage cathodes were galvanostatically evaluated. The results show that the structure of the materials does not change after coating. The optimized coating content of Al_2O_3 is 2.0%, corresponding to the layer of 20-30 nm. The electrochemical performances of LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 cathode materials are obviously improved by the Al_2O_3 layer. At the range of 2.8-4.5 V, the first discharge specific capacity of uncoated LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 materials is 175 mAh/g at 0.2 C, and the capacity retention after 50 cycles is 91.8%. At the same charge-discharge conditions, the first specific discharge capacity of coated LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 materials increases to 181 mAh/g, and the capacity retention after 50 cycles still reaches 97.4%. Even at 5 C, the discharge specific capacity of coated LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 materials is 152 mAh/g. The coated LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 materials exhibit huge potential in the lithium ion batteries with high energy density and long cycle life

Selenium-Infused Ordered Mesoporous Carbon for Room-Temperature All-Solid-State Lithium-Selenium Batteries with Ultrastable Cyclability

\Selenium with a similar reaction mechanism with sulfur and a much higher electronic conductivity is considered to be a promising cathode for all-solid-state rechargeable batteries. Herein, selenium-infused ordered mesoporous carbon composites (Se/CMK-3) are successfully prepared by a melt-diffusion method from a ball-milled mixture of Se and CMK-3 (Se-CMK-3). Furthermore, their electrochemical performances are evaluated in all-solid-state lithium-selenium batteries at room temperature. Typically, Li/75%Li2S-24%P2S5-1%P2O5/Li10GeP2S12/Se/CMK-3 all-solid-state lithium-selenium batteries exhibit high reversible capacity of 488.7 mAh g(-1) at 0.05 C after 100 cycles. Even being cycled at 0.5C, it still maintains a discharge capacity of 268.7 mAh g(-1) after 200 cycles. The excellent electrochemical performances could be attributed to the enhanced electronic/ionic conductivities and structural integrity with the addition of the CMK-3 matrix

Bio-inspired Nanoscaled Electronic/Ionic Conduction Networks for Room-Temperature All-Solid-State Sodium-Sulfur Battery

Sulfur cathode with nano-scaled electronic/ionic network is essential for all-solid-state Na/S batteries to achieve high energy density and long cycle life. However, it is great challenged to fabricate such a structure using either mechanical milling or liquid-phase reaction method. Here, a S-Na3SbS4-C cathode with distributed micro-scaled primary electronic/ionic highways along with nano-scaled secondary local-roads is fabricated by combining the liquid-phase reaction and mechanical milling. The formation mechanism for nano-scaled local-roads in S-Na3SbS4-C is systematically investigated. The S-Na3SbS4-C nanocomposite cathode with 3D distributed primary and secondary ionic/electronic conduction network provides a high initial discharge capacity of 1504.3 mAh g(-1) at 50 mA g(-1) with Coulombic efficiency of 98.5% at room temperature. Meanwhile, S-Na3SbS4-C/Na cells also demonstrate excellent rate capability with capacities of 1386.3, 1324.1, 1150.8, 893.4, 825.6, 771.2 and 662.3 mAh g(-1) at current densities of 50, 100, 200, 300, 500, 1000 and 2000 mA g(-1), respectively. Even at ultrahigh cathode loading of 6.34 and 12.74 mg cm(-2), the S-Na3SbS4-C/Na cells can deliver reversible discharge specific capacities of 742.9 and 465.6 mAh g(-1) at 100 mA g(-1), respectively. S-Na3SbS4-C/Na cell represents one of the best rate performances for room-temperature all-solid-state sodium-sulfur batteries reported to date. This work provides a simple strategy to design mixed conductive composite cathode for high-performance room-temperature all-solid-state sodium-sulfur batteries. (C) 2020 Elsevier Ltd. All rights reserved

High ion conductive Sb2O5-doped beta-Li3PS4 with excellent stability against Li for all-solid-state lithium batteries

The combination of high conductivity and good stability against Li is not easy to achieve for solid electrolytes, hindering the development of high energy solid-state batteries. In this study, doped electrolytes of Li3P1-xSbxS4-2.5xO2.5x are successfully prepared via the high energy ball milling and subsequent heat treatment. Plenty of techniques like XRD, Raman, SEM, EDS and TEM are utilized to characterize the crystal structures, particle sizes, and morphologies of the glass-ceramic electrolytes. Among them, the Li3P0.98Sb0.02S3.95O0.05 (x = 0.02) exhibits the highest ionic conductivity (similar to 1.08 mS cm(-1)) at room temperature with an excellent stability against lithium. In addition, all-solid-state lithium batteries are assembled with LiCoO2 as cathode, Li10GeP2S12/Li3P0.98Sb0.02S3.95O0.05 as the bi-layer electrolyte, and lithium as anode. The constructed solid-state batteries delivers a high initial discharge capacity of 133 mAh g(-1) at 0.1C in the range of 3.0-4.3 V vs. Li/Li+ at room temperature, and shows a capacity retention of 78.6% after 50 cycles. Most importantly, the all-solid-state lithium batteries with the Li10GeP2S12/Li3P0.98Sb0.02S3.95O0.05 electrolyte can be workable even at - 10 degrees C. This study provides a promising electrolyte with the improved conductivity and stability against Li for the application of all-solid-state lithium batteries

High ion conductive Sb2O5-doped beta-Li3PS4 with excellent stability against Li for all-solid-state lithium batteries

The combination of high conductivity and good stability against Li is not easy to achieve for solid electrolytes, hindering the development of high energy solid-state batteries. In this study, doped electrolytes of Li3P1-xSbxS4-2.5xO2.5x are successfully prepared via the high energy ball milling and subsequent heat treatment. Plenty of techniques like XRD, Raman, SEM, EDS and TEM are utilized to characterize the crystal structures, particle sizes, and morphologies of the glass-ceramic electrolytes. Among them, the Li3P0.98Sb0.02S3.95O0.05 (x = 0.02) exhibits the highest ionic conductivity (similar to 1.08 mS cm(-1)) at room temperature with an excellent stability against lithium. In addition, all-solid-state lithium batteries are assembled with LiCoO2 as cathode, Li10GeP2S12/Li3P0.98Sb0.02S3.95O0.05 as the bi-layer electrolyte, and lithium as anode. The constructed solid-state batteries delivers a high initial discharge capacity of 133 mAh g(-1) at 0.1C in the range of 3.0-4.3 V vs. Li/Li+ at room temperature, and shows a capacity retention of 78.6% after 50 cycles. Most importantly, the all-solid-state lithium batteries with the Li10GeP2S12/Li3P0.98Sb0.02S3.95O0.05 electrolyte can be workable even at - 10 degrees C. This study provides a promising electrolyte with the improved conductivity and stability against Li for the application of all-solid-state lithium batteries

Poly(vinylidene fluoride) nanofibrous mats with covalently attached SiO 2 nanoparticles as an ionic liquid host: enhanced ion transport for electrochromic devices and lithium-ion batteries

In this article, it is demonstrated that the electrospun poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF–HFP)) nanofibrous mat functionalized with (3-aminopropyl)triethoxysilane is a versatile platform for the fabrication of hybrid nanofibrous mats by covalently attaching various types of inorganic oxide nanoparticles on the nanofiber surface via a sol–gel process. In particular, SiO2-on-P(VDF–HFP) nanofibrous mats synthesized using this method is an excellent ionic liquid (IL) host for electrolyte applications. The IL-based electrolytes in the form of free-standing mats are obtained by immersing SiO2-on-P(VDF–HFP) mats in two types of liquid electrolytes, namely LiClO4/1-butyl-3-methylimidazolium tetrafluoroborate and bis(trifluoromethane)sulfonimide lithium salt/1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide. It is found that the surface attached SiO2 nanoparticles can effectively serve as salt dissociation promoters by interacting with the anions of both ILs and lithium salts through Lewis acid–base interactions. They dramatically enhance the ionic conductivity and lithium transference number of the electrolytes. In addition, better compatibility of the electrolytes with lithium electrodes is also observed in the presence of surface-attached SiO2. Using IL-loaded SiO2-on-P(VDF–HFP) nanofibrous mats as the electrolytes, electrochromic devices display higher transmittance contrast, while Li/LiCoO2 batteries show significantly improved C-rate performance and cycling stability. This class of novel non-volatile electrolytes with high ionic conductivity also has the potential to be used in other electrochemical devices.ASTAR (Agency for Sci., Tech. and Research, S’pore)Published versio