Natural halloysite was used as precursor and template to prepare silicon nanotubes through low temperature aluminothermic reduction. The mechanism of variation in morphology during the reduction process and the lithium storage performance of the silicon nanotube were studied. It was found that the alumina octahedron in the natural halloysite was helpful to maintain the one-dimensional nanotube structure of the products during the low temperature aluminothermic reduction process, leading to the formation of silicon nanotubes. The silicon nanotubes had excellent electrochemical performance when used as anode of lithium-ion batteries, with an initial specific capacity of 3 150 mA·h/g. After 50 cycles, the specific capacity was still 1 977 mA·h/g, which is more than twice the value of commercial silicon anode. At a current density of 2 A/g, the capacity was maintained to be 913 mA·h/g after 200 cycles, which is also much higher than that of commercial silicon anode.

All-solid-state lithium batteries become popular due to their high energy density, high safety, and wide electrochemical window. However, there are also some problems in the practical applications, such as the rigid contact between solid electrolyte and electrode material, side reactions occurring readily in contact with electrolyte because of active lithium metal causing the interface to be unstable, sulfide solid electrolyte being unstable to air and high production costs. This review summarized some research work on the interface between electrode material and oxide solid electrolyte, sulfide solid electrolyte, and polymer solid electrolyte, analyzed the interface problems, and discussed the interface optimization strategies to solve the interface problems of all solid-state lithium batteries in the future.

At intermediate and low temperatures, the increase in electrolyte resistance and the decrease in the catalytic activity of electrodes can restrict solid oxide fuel cells (SOFCs) performance. The oxidation of the interconnects leads to the degradation in the output performance of SOFCs. Therefore, various thin film technologies are used to reduce the internal resistance of SOFCs, improve the electrode activity, and enhance the oxidation resistance of interconnects. Among these technologies, pulsed laser deposition (PLD) is widely used in the fabrication of the thin films for ILT-SOFCs due to its easily controlled feature, environmental friendliness, uniform composition between target and film, and capability of depositing multilayer films. The research work on PLD technology in the preparation of electrolyte, electrodes and interconnect of ILT-SOFCs were reviewed comprehensively. The existing research work show that PLD can increase the surface activity of the electrode, significantly reduce the ohmic resistance and effectively block the electron conduction of electrolyte. The protective film deposited by PLD can retard the oxidation of the interconnect. The improvements in these components increase the performance of SOFCs. Finally, the future development of PLD in SOFC manufacture was given.

Ni-YSZ anode supportors with straight pores as well as an integrated Ni-YSZ anode supportor/functional layer were prepared by an alginate ion gel method. A large number of the through-holes are parallelly distributed in the straight-pored Ni-YSZ anode supports with a pore diameter of approximately 80 μm. The thickness of Ni-YSZ anode functional layer fabricated by a spin-coating method is 130 μm. The pores with the diameters of 20-60 μm of the integrated anode support are divergent distributed, and the thickness of the anode functional layer is only 24 μm. Using the integrated method can reduc the time and cost of the preparation procedure. The solid oxide fuel cell supported by the straight-pored Ni-YSZ anode and the single cell based on the integrated substrates possessa maximum power density of 258 mW/cm² and 365 mW/cm² at 800℃, respectively, when using H₂ as a fuel and air as an oxidant.

An Al—In—Mg—Sn—Ce alloy anode was prepared. The effect of annealing condition on the electrochemistry properties of the alloy anode was analyzed via the measurements of hydrogen evolution rate, polarization curve, electrochemical impedance and constant current discharge. The microstructure and corrosion morphology of the alloy anode were determined by electron probe microanalyzer and scanning electron microscopy. The results show that the annealing treatment has a certain effect on the number and size of precipitates on the alloy surface, thus improving the electrochemical activity and corrosion resistance of the alloy anode. Also, the Al—In—Mg—Sn—Ce alloy anode material has an excellent discharge performance in an actual use process when the annealing condition is 350℃ and 6 h. Tthe energy density is the maximum value, and its energy density is 4 837.64 W·h/kg and 3 283.62 W·h/kg when the aluminum alloy anode is discharged at the current density of 40 mA/cm² and 100 mA/cm², respectively.

Chopped carbon fiber (CF) was used as a conductive material to prepare alkali-activated slag/fly ash conductive mortar. The effects of carbon fiber content, stress loading amplitude and loading rate on the conductivity, mechanical properties and self-sensing properties of carbon fiber-alkali-activated conductive mortar were investigated. The results show that the alkali-activated conductive mortar reaches the percolation threshold and forms a conductive path when the volume fraction of carbon fiber is 0.2%. The mixture has a stable self-sensing performance with a high gauge factor at different loading rates and stress amplitudes. The self-sensing performance of alkali-activated slag/fly ash is the optimum with a gauge factor of 175, which is one order of magnitude greater than that of carbon fiber-cement mortar, when the stress amplitude is 12 MPa and the loading rate is 2.0 kN/s.

CoNiO₂/Ti₃C₂T_x composite was prepared by a facile co-precipitation method and subsequent heat treatment. The as-prepared samples were characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, nitrogen adsorption-desorption measurement, cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. The results demonstrate that CoNiO₂/Ti₃C₂T_x composite with a CoNiO₂∶Ti₃C₂T_x mass ratio of 30∶1 exhibits the optimum electrochemical performance. The specific capacitance of CoNiO₂/Ti₃C₂T_x composite is 389 F/g at a current density of 1 A/g, which is approximately 6 times greater than that of Ti₃C₂T_x. CoNiO₂/Ti₃C₂T_x composite has the specific capacitance of 309 F/g when the current density increases to 20 A/g, and shows a cycle stability with 82% capacitance retention after 1 500 charge-discharge cycles at a current density of 10 A/g.

The high-purity r-BN nanosheets were synthesized at 1 100℃ by using KBH₄ and NH₄Cl as raw materials, NaCl and KCl as molten salt medias. The effects of salt-free and molten-salt methods on the phase composition and crystal morphology of r-BN were studied. And the electrochemical performance of r-BN was tested. Compared with the salt-free method, the molten-salt method can be used to prepare high-crystallinity and good-shaped sheet r-BN at the same temperature. r-BN shows good cycle stability. The specific capacitance of r-BN at a current density of 1 A/g is 16.35 F/g, and r-BN shows a small charge-transfer resistance and internal resistance.

Li_1.02Ni_0.05Mn_1.93O₄(LNMO) cathode materials were synthesized via liquid flameless combustion at 500℃ for 1 h and subsequent calcination at 700℃ for 3, 6, 9 h and 12 h. The effect of calcination time on the structure, morphology, electrochemical and kinetic properties of the LNMO samples was investigated. The results show that all the samples synthesized have a spinel structure of LiMn₂O₄, and the particle size and crystallinity increase with the increase of calcination time. The LNMO-6 sample has a superior electrochemical performance (i.e., the first discharge specific capacity of 118.7 mA·h/g and the capacity retention rate of 87.0% after 200 cycles at 1 C). At high rates of 5 C and 10 C, the LNMO-6 sample still maintains capacity retention rates of 76.3% and 75.5% after 1 000 cycles. Based on the results by cyclic voltammetry and electrochemical impedance spectroscopy, the LNMO-6 sample has the maximum diffusion coefficient (i.e., 3.74×10^-15 cm²/s) and the minimal apparent activation energy (i.e., 22.72 kJ/mol).

The structure stability, electronic structure properties and mechanical properties of Li_xCoO₂(0≤x≤1) as cathode material for lithium-ion battery were investigated by the first principles method based on density functional theory. The results show that the crystal structure of Li_xCoO₂ changes from hexagonal structure to monoclinic P2/m structure as x = 0.5, and then changes to hexagonal structure as x = 0. The conduction band of Li_xCoO₂ is partially filled and the valence band is completely filled with the de-intercalation of Li atom. As a result, the metal property and the electron conductivity of Li_xCoO₂ both increase, and the spin polarization phenomenon appears. The Co—O bond in Li_xCoO₂ is a covalent bond partially with an ionic bond. The ionic properties of Co—O bond weaken and the covalent properties increase with the de-intercalation of Li atom. The bulk modulus (B), shear modulus (G) and Young's modulus of Li_xCoO₂ decrease with the de-intercalation of Li atom, while the Poisson ratio and the anisotropy index increase. The change of G/B value shows that LiCoO₂ is brittle and then changes to ductile during de-intercalation process.