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Monodispersed spherical Li 1.3 Al 0.3 Ti 1.7 (PO 4) 3 (LATP) precursor particles are prepared by hydrolysis-complexation combined with spray-drying processes, and the desirable targeted LATP-900 particles are obtained after being calcinated at 900 °C in air confirmed by thermogravimetry-differential scanning calorimetry and X-ray diffraction analyses. The high compacted density of the particles with normal size distribution can be conductive to collecting the compacted LATP pellets, which can reach as high as 1.608 × 10−4 S cm−1 of ionic conductivity at 30 °C. The assembled LiCoO 2 /LATP-900/Li cell can stably deliver 138.2 mAh g−1 of discharge specific capacity after only four cycles and quickly recover to 132.3 mAh g−1 after 80 cycles when the current is set back to 0.1 C with nearly 100% coulombic efficiency, which suggests that the LATP-900 pellet can become a promising candidate for the high performance solid lithium ion batteries. [ABSTRACT FROM AUTHOR]

To improve the ionic conductivity as well as enhance the mechanical strength of the gel polymer electrolyte, poly(vinylidene fluoride-hexafluoroprolene) (P(VDF-HFP))-based composite polymer electrolyte (CPE) membranes doped with the organic-inorganic hybrid particles poly(methyl methacrylate) -ZrO 2 (PMMA-ZrO 2 ) are prepared by phase inversion method, in which PMMA is successfully grafted onto the surface of the homemade nano-ZrO 2 particles via in situ polymerization confirmed by FT-IR. XRD and DSC patterns show adding PMMA-ZrO 2 particles into P(VDF-HFP) can significantly decrease the crystallinity of the CPE membrane. The CPE membrane doped with 5  wt % PMMA-ZrO 2 particles can not only present a homogeneous surface with abundant interconnected micro-pores, but maintain its initial shape after thermal exposure at 160 °C for 1 h, in which the ionic conductivity and lithium ion transference number at room temperature can reach to 3.59 × 10 −3  S cm −1 and 0.41, respectively. The fitting results of the EIS plots indicate the doped PMMA-ZrO 2 particles can significantly lower the interface resistance and promote lithium ions diffusion rate. The Li/CPE-sPZ/LiCoO 2 and Li/CPE-sPZ/Graphite coin cells can deliver excellent rate and cycling performance. Those results suggest the P(VDF-HFP)-based CPE doped with 5  wt % PMMA-ZrO 2 particles can become an exciting potential candidate as polymer electrolyte for the lithium ion battery. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ti4+ doping can provide a stronger Ti-O bond to strengthen the structural stability. • NCM83-2.0 presents compact secondary particles with more ordered layered structure. • NCM83-2.0 delivers 170.5 mAh g−1 and 92.2 % after 100cycles at 2.0 C and 60 °C. • NCM83-2.0 preserves the structural integrity of secondary particles after cycles. The further commercialization of layer-structured Ni-rich LiNi 0.83 Co 0.11 Mn 0.06 O 2 (NCM83) cathode for high-energy lithium-ion batteries (LIBs) has been challenged by severe capacity decay and thermal instability owing to the microcracks and harmful phase transitions. Herein, Ti4+-doped NCM83 cathode materials are rationally designed via a simple and low-cost in-situ modification method to improve the crystal structure and electrode–electrolyte interface stability by inhibiting irreversible polarizations and harmful phase transitions of the NCM83 cathode materials due to Ti4+-doped forms stronger metal-O bonds and a stable bulk structural. In addition, the optimal doping amount of the composite cathode material is also determined through the results of physical characterization and electrochemical performance testing. The optimized Ti4+-doped NCM83 cathode material presents wider Li+ ions diffusion channels (c = 14.1687 Å), lower Li+/Ni2+ mixing degree (2.68 %), and compact bulk structure. The cell assembled with the optimized Ti4+-doped NCM83 cathode material exhibits remarkable capacity retention ratio of 95.4 % after 100cycles at 2.0 C and room temperature, and outstanding reversible discharge specific capacity of 148.2 mAh g−1 at 5.0 C. Even under elevated temperature of 60 °C, it delivers excellent capacity retention ratio of 92.2 % after 100cycles at 2.0 C , which is significantly superior to the 47.9 % of the unmodified cathode material. Thus, the in-situ Ti4+-doped strategy presents superior advantages in enhancing the structural stability of Ni-rich cathode materials for LIBs. [ABSTRACT FROM AUTHOR]

NASICON-type fast ion conductor powders Li 1.3 Al 0.3 Ti 1.7 (PO 4) 3 (LATP) are prepared by spray-drying and sintering processes confirmed by XRD and SEM analyses. Novel poly(vinylidene fluoride-hexafluoropylene) (P(VDF-HFP))-based composite polymer electrolytes (CPEs) doped with various amounts of LATP particles are fabricated via classical inverse-phase method. As a result, the as-prepared CPE-5 membrane can present excellent physicochemical properties when the doped amount is maintained at 5% vs. polymer matrix, in which the interfacial impedance value can rapidly stabilize at 472 Ω and the thermal decomposition temperature can be up to 430 °C, respectively. In particularly, the ionic conductivity can be as high as 3.943 mS cm−1 at 25 °C. In addition, the assembled LiCoO 2 /CPE-5/Li coin cell can deliver a discharge specific capacity of 145.4 mAh g−1 at 1.0 C with 96.93% capacity retention ratio after 25 cycles. These outstanding properties can promote the CPE-5 to be a candidate electrolyte to improve the performance of lithium ion batteries. Brief preparation process and characterization of composite polymer electrolytes doped with various amounts of LATP powders. Unlabelled Image • NASICON-type LATP powders are prepared by spray-drying and sintering methods. • The optimum LATP doping amount is 5% vs. polymer matrix. • The ionic conductivity at room temperature is as high as 3.943 mS cm−1. • The assembled cell delivers a discharge specific capacity of 132.8 mAh g−1 at 1.0 C. [ABSTRACT FROM AUTHOR]

Using industrial, low-cost and easily available AlSiFe alloy powders as the precursor, the porous composite of silicon and silica containing iron with conductive carbon shell (Si-SiO 2 @Fe/C) are prepared by alkali etching combined with following pyrolysis process, in which the silicon nanoparticles are evenly embedded in the porous layered silica templates containing iron confirmed by scanning electron microscopy and X-ray diffraction analyses. The remained iron and fabricated porous structure as well as the coated carbon layer in the composite can not only alleviate the volume effect of silicon particles, but also enhance the conductivity of the electrode materials, which can result in excellent cyclic stability (830 mAh g−1 after 200 cycles at 200 mA g−1 with coulombic efficiency >99%), remarkable rate capability (reversible discharge specific capacity of 950, 900, 800, 650 and 500 mAh g−1 at 100, 200, 500, 1000 and 2000 mA g−1, respectively), low transfer resistance (35.71 Ω after 200 cycles at 200 mA g−1) and enhanced diffusion coefficient of lithium ions (increasing from 4.453E−15 cm2 s−1 to 2.945E−13 cm2 s−1 after 200 cycles). These outstanding results can ensure the targeted Si-SiO 2 @Fe/C composite as a promising anode for lithium ion batteries. Schematic illustrations of the preparation processes for the Si-SiO 2 @Fe/C materials. Unlabelled Image • Porous Si-SiO 2 @Fe/C anode is prepared by alkali etching and pyrolysis process. • Porous structure can alleviate the volume effect of Si particles. • The remained Fe can enhance the conductivity as well as small capacity. • The anode presents low transfer resistance and high Li+ diffusion coefficient. • The assembled coin cells show excellent rate and cycle performance. [ABSTRACT FROM AUTHOR]

Novel NASICON-type structural Li 1.3 Al 0.3 Ti 1.7 Si x P 5(3-0.8x) O 12 (LATSP) solid electrolytes are synthesized by spray-drying combined with sintering methods, and the corresponding physicochemical properties are investigated by X-ray diffraction, Field emission scanning electron microscope, Fourier transform infrared spectrometer and X-ray photoelectron spectroscopy. The targeted LATSP powders present uniform cube-like morphology and excellent crystallinity, in which the LATSP-0.05 solid electrolyte exhibits a high ionic conductivity of 1.053 E-4 S cm−1 and a low activation energy of 0.44 eV at 25 °C as well as a high compaction density of 2.892 g cm−3 when the content of Si doping retains 5% vs. the molar ratio of the pure Li 1.3 Al 0.3 Ti 1.7 (PO 4) 3. Furthermore, the assembled LiCoO 2 /LATSP-0.05/Li all-solid-state coin cell can achieve a relatively high initial discharge specific capacity of 116.2 mAh g−1 at 0.1 C and possess outstanding cycle and rate performance compared to other cells at room temperature. These results show that the novel LATSP-0.05 solid electrolyte with NASICON-type structure is expected to widely employ in the field of all-solid-state lithium ion batteries. Preparation schemes of novel NASICON-type structural Li 1.3 Al 0.3 Ti 1.7 Si x P 5(3-0.8x) O 12 solid electrolytes. Unlabelled Image • NASICON-type structural Li 1.3 Al 0.3 Ti 1.7 Si x P 5(3-0.8x) O 12 solid electrolytes are synthesized. • The LATSP-0.05 exhibits uniform morphology and excellent crystallinity. • Ionic conductivity and activation energy are 0.105 mS cm−1 and 0.44 eV, respectively. • The assembled all-solid-state cell presents outstanding cycle and rate performance. [ABSTRACT FROM AUTHOR]

A novel sphere-like SnO 2 /TiO 2 composite is synthesized via spray-drying followed by calcination as confirmed by X-ray diffraction and field emission-scanning electron microscopy analyses; the SnO 2 /TiO 2 composite is composed of the tetragonal cassiterite-like SnO 2 nanoparticles and anatase-like TiO 2 nanospheres. The characterization results show that the optimal stoichiometric ratio of SnO 2 /TiO 2 is approximately 3:1 when the composite serves as the anode for lithium ion batteries, in which the composite electrode not only delivers a high initial discharge specific capacity of 1476 mAh g−1 and retains 483 mAh g−1 after 40 cycles at 500 mA g−1 but also presents a low transfer resistance of approximately 56.33 Ω, a high Warburg coefficient of up to 85.82 Ω cm2 s−0.5, and a high lithium ion diffusion coefficient of approximately 6.934 E-15 cm2 s−1 at ambient temperature. These excellent electrochemical properties suggest that the SnO 2 /TiO 2 composite electrode may be a promising anode material for lithium ion batteries. [ABSTRACT FROM AUTHOR]