Porous Li1 Research Articles

Lithium ion adsorption characteristics of porous Li1.33Mn1.67O4 adsorbent prepared using petroleum-based pitch as a binder

The lithium manganese oxide (LMO) Li1.33Mn1.67O4 exhibits a spinel structure and is well known as a highly selective adsorbent for extracting lithium from salt lakes or seawater. For practical use, the LMO powder should be transformed into porous shapes, such as granules, spheres, or foams, by using appropriate binding materials. In this study, we have proposed an alternative approach for the preparation of porous LMO adsorbents; this involves the use of petroleum pitch as a binding material and subsequent formation of a mixture and heat treatment, which provide chemical resistance and mechanical strength. Disc-shaped porous LMO/C adsorbents were prepared without any structural changes in the spinel structure of the LMO powder after heat treatment. The prepared LMO/C adsorbent treated with acid (and converted to HMO/C) showed excellent adsorption capacity and mechanical durability. The theoretical maximum adsorption capacity of the disc-shaped HMO/C adsorbent was 24 mg g−1. We also tested HMO/C adsorbent to the recovery of lithium from actual brine to confirm the feasibility of suggested method.

Solid Polymer Electrolyte Reinforced with a Li1.3Al0.3Ti1.7(PO4)3-Coated Separator for All-Solid-State Lithium Batteries.

Poly(ethylene oxide) (PEO)-based solid-state lithium batteries (SSLBs), accompanied by potential high energy density and reliable safety, have attracted wide attention. However, PEO-based solid-state electrolytes (SSEs) are hard to scale up due to their low oxidation stability, low ionic conductivity at room temperature, and relatively poor mechanical properties. Here, a PEO-based ceramic-polymer (PCP) composite SSE is designed. The porous Li1.3Al0.3Ti1.7(PO4)3 (LATP)-coated polyethylene (PE) separator is filled with PEO/lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) solution, which possesses both a robust mechanical property and processable flexibility. The results show the PCP membrane effectively suppresses the growth of lithium (Li) dendrites identified by a flat Li deposition. It is attributed to the robustness of the PCP membrane itself and the formation of a mixed ionic/electronic conducting interphase (MCI) intertwined with a solid electrolyte interface (SEI) between the PCP membrane and the Li anode. The MCI-SEI intertwined mixed phase facilitates the homogeneous Li deposition and enhances the cycle stability of the electrolyte/anode interface. Hence, the PCP membrane effectively prevents short-circuiting and shows a good cycling stability of more than 2000 h in a Li/PCP/Li symmetric cell with a current density of 0.2 mA cm-2 at 60 °C. Moreover, the Li/PCP/LiFePO4 all-solid-state battery shows a stable cycling performance with 160 mAh g-1 at 0.2C after 200 cycles at 60 °C. The results show the purposed PCP membrane based on a LATP-coated PE separator is easy to be fabricated and could be practical for many applications.

Modeling of solid-state lithium-oxygen battery with porous Li1.3Al0.3Ti1.7(PO4)3-based cathode

Solid-state lithium-oxygen batteries have attracted great attention due to their high theoretical energy density, excellent safety, and cycle stability. The present study establishes a new, highly efficient mathematical model for a solid-state lithium-oxygen battery, which utilizes a porous Li1.3Al0.3Ti1.7(PO4)3 (LATP) solid electrolyte sheet as the cathode. The study includes and considers the transport of lithium ions and oxygen molecules, the kinetic equation of electrochemical reaction, and the charge conservation equation. The active surface area of the cathode is calculated by the binary particle mixed percolation theory, and a product growth model is proposed to describe the active surface's evolution. Validated by experimental data, the model can predict both the voltage specific capacity curves under different currents and the electrode behavior of discharge. The results show that the initial cathode active surface area and battery capacity are sensitive to such factors as LATP particle radius, LATP volume fraction, and carbon particle radius. It is concluded that the discharge product in solid-state lithium-oxygen battery has more uniformly distributed, which aids in oxygen diffusion and a longer discharge process.

Composite polymer electrolyte with three-dimensional ion transport channels constructed by NaCl template for solid-state lithium metal batteries

In order to meet the challenges brought by the low ionic conductivity of solid-state electrolytes (SSEs) and the growth of lithium dendrites in all-solid-state lithium metal batteries (ASSLMBs), the composite polymer electrolytes (CPEs) constructed by the combination of three-dimensional (3D) porous ceramics framework and polymers have been widely studied. However, there are still many challenges to preparation of 3D high-strength porous ceramics framework by a simple way. Here, we designed a 3D interconnected porous Li1.3Al0.3Ti1.7(PO4)3 (LATP) framework using NaCl as the template, which not only provides the fast transport channels for Li+ but also serves as a physical barrier to suppress the growth of Li dendrites. Benefiting from the enhanced mechanical and ionic conductivity of the 3D interconnected porous LATP framework, Li/Li symmetric cells based on the prepared CPE can cycle over 1000 h at 0.2 mA cm−2, 0.2 mAh cm−2 and 2000 h at 0.1 mA cm−2, 0.1 mAh cm−2. Moreover, all-solid-state LFP/Li with this 3D CPE demonstrates long-term stability cycles at 1 C.

In Situ Polymerization Permeated Three-Dimensional Li+-Percolated Porous Oxide Ceramic Framework Boosting All Solid-State Lithium Metal Battery.

Solid‐state lithium battery promises highly safe electrochemical energy storage. Conductivity of solid electrolyte and compatibility of electrolyte/electrode interface are two keys to dominate the electrochemical performance of all solid‐state battery. By in situ polymerizing poly(ethylene glycol) methyl ether acrylate within self‐supported three‐dimensional porous Li1.3Al0.3Ti1.7(PO4)3 framework, the as‐assembled solid‐state battery employing 4.5 V LiNi0.8Mn0.1Co0.1O2 cathode and Li metal anode demonstrates a high Coulombic efficiency exceeding 99% at room temperature. Solid‐state nuclear magnetic resonance results reveal that Li+ migrates fast along the continuous Li1.3Al0.3Ti1.7(PO4)3 phase and Li1.3Al0.3Ti1.7(PO4)3/polymer interfacial phase to generate a fantastic conductivity of 2.0 × 10−4 S cm−1 at room temperature, which is 56 times higher than that of pristine poly(ethylene glycol) methyl ether acrylate. Meanwhile, the in situ polymerized poly(ethylene glycol) methyl ether acrylate can not only integrate the loose interfacial contact but also protect Li1.3Al0.3Ti1.7(PO4)3 from being reduced by lithium metal. As a consequence of the compatible solid‐solid contact, the interfacial resistance decreases significantly by a factor of 40 times, resolving the notorious interfacial issue effectively. The integrated strategy proposed by this work can thereby guide both the preparation of highly conductive solid electrolyte and compatible interface design to boost practical high energy density all solid‐state lithium metal battery.

Preparation of porous Li1.2Mn0.54Ni0.13Co0.13O2 micro-cubes for high-capacity lithium-ion batteries

Abstract We report on the preparation of Li1.2Mn0.54Ni0.13Co0.13O2 micro-cubes for the applications of high-capacity lithium-ion batteries. Metal oxalate precursors with a cubic morphology are firstly prepared via a coprecipitation method in the mixed solutions containing ethanol, methanol and water. After controlled calcination treatment, the metal oxalate precursors are transformed into Li-rich layered oxide micro-cubes which possess a porous micro-nano structure consisting of interconnected nano-sized subunits. It is observed that a small amount of Li4Mn5O12 spinel is integrated with the layered phase in the micro-cubes. Compared with the micro-long-rod counterpart which is prepared under similar condition but only possess layered structure, the micro-cube cathode has excellent electrochemical properties that not only possess a high capacity of 278 mA h g−1 with an initial Coulombic efficiency of 88.3%, but also outstanding capacity retentions of 99.3% after 100 cycles and 89.7% after 200 cycles at 1 C. The excellent electrochemical properties of Li1.2Mn0.54Ni0.13Co0.13O2 micro-cube cathode may arise from the contributions from both the porous micro-nano structure and Li4Mn5O12 spinel phase, which can enhance the efficient contact of electrolyte and the transportation of Li+ as well as maintain the structure stability.

A cross-like hierarchical porous lithium-rich layered oxide with (110)-oriented crystal planes as a high energy density cathode for lithium ion batteries

Cross-like hierarchical porous Li1.167Mn0.583Ni0.250O2 with (110)-oriented crystal planes (CHP-LMNO) is successfully developed by a morphology-conserved solid-state Li implantation method.

The enhancement of rate and cycle performance of LiMn2O4 at elevated temperatures by the synergistic roles of porous structure and dual-cation doping

Spinel LiMn2O4-based cathode material has been successfully commercialized for power lithium ion batteries for large-scale applications in pure electric vehicles. However, pure LiMn2O4 suffers from poor rate performance and fast capacity fading especially at elevated temperatures derived from Mn dissolution and structural distortion. Herein, a study on the rate and cycle performance of single/double-cation doped porous LiMn2O4 microspheres, which was prepared by an easy method using porous MnCO3 microspheres as a self-supporting template, was performed. The as-synthesized porous Li1.02Co0.05Mn1.90Li0.05O4 (LMO-S4) microspheres constructed with nanometer-sized primary particles show an obvious enhancement of cyclability over other LiMn2O4-based materials such as Li1.02Mn2O4 (LMO-S1), Li1.02Mn1.95Li0.05O4 (LMO-S2) and Li1.02Co0.05Mn1.95O4 (LMO-S3), especially at an elevated temperature (55 °C). The obtained LMO-S4/lithium half cells deliver capacities of 113.1 and 109.0 mAh g−1 at 1.0 and 5 C, respectively, with the corresponding capacity retentions of 88.9 and 90.2% for up to 1000 cycles. Meanwhile, it can deliver an initial capacity of 114.0 mAh g−1 at 5 C with a capacity retention of 80.1% after 1000 cycles at 55 °C. Furthermore, it displays superior rate performance and cycle performance at 0 °C with a specific capacity of 106 mAh g−1, and the capacity retention is 79.6% after 1000 cycles at 5 C. These results reveal that a dual-doping strategy and porous structure design play synergistic roles in the preparation of high performance LiMn2O4-based spinel cathode material. The cation co-doped strategy can maintain the crystal structural stability and provide interfacial stability while preserving fast Li+ diffusion during the long-time cycling at elevated temperatures. Furthermore, the porous structure favors fast Li+ intercalation/deintercalation kinetics by allowing electrolyte insertion through the nanoparticles during the reversible electrochemical process. Lithium and cobalt co-doped LiMn2O4 with a nominal composition of Li1.02Co0.05Mn1.90Li0.05O4 exhibits an obviously improved cycle performance at high temperature than that of single-doped LiMn2O4.

Synthesis and characterization of electrospun aluminum doped Li1.6Mn1.6O4 spinel

Three dimensional porous Li1.6Al0.6MnO4 (LAMO) nanofibers were successfully prepared for the first time, via a facile electrospinning homogenous solution of lithium acetate, manganese nitrate and aluminum nitrate in polyvinyl alcohol and polyvinylpyrolidone solution followed by calcination of the as-spun nanofibers at 500, 700 and 900°C. The processing parameters were; voltage 25kV, flow rate 0.7ml/h, the distance between the needle and collector 10cm and the inner diameter of the needle 0.499mm. X-ray diffraction of the samples prepared by using electrospinning and sol–gel revealed that Li1.6Al0.6MnO4 phase was formed at; 500°C and 700°C, respectively. Field Emission Scanning Electron Microscopy revealed that the electrospun nanofibers at 700°C were fabricated with diameter 250nm, and the single fiber composed of 30nm LAMO grains. On the other hand, samples calcined at 700°C, prepared by sol–gel, show coalescence of the fine grains of LAMO in the form of microspheres with an average diameter of 1µm and each microsphere is composed of fine crystals of LAMO. The characteristics of the prepared spinel make them promising for use in lithium adsorption from polluted effluents.

Urea‐assisted combustion synthesis of porous Li 1.2 Ni 0.13 Co 0.13 Mn 0.54 O 2 microspheres as high‐performance lithium‐ion battery cathodes

An initial urea-assisted combustion and subsequent high-temperature crystallisation route have been used to prepare porous Li1.2Ni0.13Co0.13Mn0.54O2 microspheres. The as obtained microspheres with the size of 2–4 μm are composed of numerous nanoparticles, and these nanoparticles with clear corner and edge have the size of 100–200 nm. A possible formation process of porous microspheres structures is discussed. As lithium-ion battery cathodes, the porous microspheres can deliver an initial discharge capacity of 252.3 mAh g−1 with high Coulombic efficiency of 80.6% at current density of 20 mA g−1, and keep a stable discharge capacity of 115.5 mAh g−1 at 1000 mA g−1. Although the sample obtained without urea only deliver a discharge capacity of 66.7 mAh g−1 at 1000 mA g−1. Maybe, the facile urea-assisted combustion route is suitable for the synthesis of lithium-rich layered oxides as lithium-ion battery cathodes.

Template GNL-assisted synthesis of porous Li1.2Mn0.534Ni0.133Co0.133O2: towards high performance cathodes for lithium ion batteries

A high performance cathode of porous Li1.2Mn0.534Ni0.133Co0.133O2 for lithium ion batteries synthesized by a GNL-template.

Polymer Template Assisted Synthesis of Porous Li1.2Mn0.53Ni0.13Co0.13O2 as a High Capacity and High Rate Capability Positive Electrode Material

A porous layered composite of Li2MnO3 and LiMn1/3Co1/3Ni1/3O2 (composition: Li1.2Mn0.53Ni0.13Co0.13O2) is prepared by reverse microemulsion method employing a soft polymer template and studied as a positive electrode material. The precursor is heated at several temperatures between 500 and 900°C. The product samples possess mesoporosity with broadly distributed pores of about 30 nm diameters. There is a decrease in pore volume as well as in surface area by increasing the temperature of preparation. Nevertheless, the electrochemical activity of the composite increases with an increase in temperature. The discharge capacity values of the samples prepared at 800 and 900°C are about 250 mAh g−1 at a specific current of 40 mA g−1 with an excellent cycling stability. A value of 225 mAh g−1 is obtained at the end of 30 charge-discharge cycles. Both these composite samples possess high rate capability, but the 800°C sample is marginally superior to the 900°C sample. A discharge capacity of 100 mAh g−1 is obtained at a specific current of 1000 mA g−1. The high rate capability is attributed to porous nature of the composite samples.

Sacrificed template synthesis of Li1.2Ni0.13Co0.13Mn0.54O2 spheres for lithium-ion battery cathodes

Porous and solid Li1.2Ni0.13Co0.13Mn0.54O2 spheres have been prepared by spherical Ni0.13Co0.13Mn0.54(CO3)0.8 and MnO2-sacrificed templates route. X-ray diffraction profiles show two kinds of Li1.2Ni0.13Co0.13Mn0.54O2 spheres have good layered structure with solid solution characteristic. Scanning electron microscope images reveal that the porous Li1.2Ni0.13Co0.13Mn0.54O2 spheres obtained from spherical carbonate precursor are composed of well-defined primary nanoparticles. These nanoparticles have the size of 100–300 nm, and some porous structure can be observed among these particles on the surface. The solid spheres obtained from MnO2 are made of tightly clustered nanoparticles. As lithium-ion battery cathodes, the porous spheres exhibit a high initial discharge capacity of 255.7 mAh g−1 at 0.1 C between 2.0 and 4.8 V. After 50 cycles, a discharge capacity of 177.7 mAh g−1 could be retained at 0.5 C. Even at high charge–discharge rate of 5 C (1,000 mA g−1), 121.4 mAh g−1 can be reached. But the solid spheres only deliver initial discharge capacity of 159.9 mAh g−1 at 0.1 C. Anyway, the different electrochemical performances of two samples should be attributed to the use of different sacrificed templates.

Synthesis of porous Li2MnO3-LiNi1/3Co1/3Mn1/3O2 nanoplates via colloidal crystal template

Abstract

Porous Glass‐Ceramics with a Skeleton of the Fast‐Lithium‐Conducting Crystal Li1+xTi2−xAlx(PO4)3

Porous glass‐ceramics with a skeleton of the fast‐lithium‐conducting crystal Li1+xTi2−xAlx(PO4)3 (where x= 0.3–0.5) were prepared by crystallization of glasses in the Li2O─CaO─TiO2─Al2O3–P2O5 system and subsequent acid leaching of the resulting dense glass‐ceramics composed of the interlocking of Li1+xTi2−xAlx(PO4)3 and β‐Ca3(PO4)2 phases. The median pore diameter and surface area of the resulting porous Li1+xTi2−xAlx(PO4)3 glass‐ceramics were approximately 0.2 μm and 50 m2/g, respectively. The electrical conductivity of the porous glass‐ceramics after heating in LiNO3 aqueous solution was 8 × 10−5 S/cm at 300 K or 2 × 10−2 S/cm at 600 K.