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Nickel-rich cathode LiNi0.83Co0.11Mn0.06O2 (NCM) has a high specific discharge capacity and low cost, and is a very promising cathode material. However, NCM exhibits poor structural and chemical stability, resulting in poor cycle stability. Surface coating can maintain structural stability, isolate cathode materials and electrolytes, and effectively improve the cycle stability of NCM. The mixed ion–electron conductor Li7.3La3Zr1.7Co0.3O12 (LZC) was coated on the surface of NCM using an anhydrous co-precipitation method, with a coating thickness of 2% (molar ratio), which promotes the conduction of electrons and ions. The coated positive electrode material was prepared into a liquid electrolyte half battery. After 200 cycles at 1 C between 2.8 and 4.5 V, the capacity retention of NCM is only 62.2%, while the capacity retention of the most excellent coating sample increased to 79.2%. [ABSTRACT FROM AUTHOR]

As a cathode material for sodium-ion batteries (SIBs), P2-Na0.67Fe0.5Mn0.5O2 has the advantages of high capacity and high working voltage. However, the irreversible phase transition of P2-O2 causes the electrochemical performances to rapidly decline with cycling. The phase stability and therefore cycle stability could be effectively improved by cation doping. The precursor Fe0.5Mn0.5CO3 is prepared by coprecipitation method. The initial discharge-specific capacity of P2-Na0.67Fe0.5Mn0.5O2 in the voltage range of 2–4.3 V is 164 mAh·g−1, and its capacity retention rate after 100 cycles is 48.6%. Mg doping can improve the cycling stability and rate capability, while slightly reducing the initial capacity. The capacity retention is improved from 48.6 to 75.3% with Mg doping. [ABSTRACT FROM AUTHOR]

A direct coupling of antiferroelectric (AFE) and resistive switching (RS) is realized for the first time in an oxide heterostructures (non‐tunneling mechanisms). This allows the resistance of the heterostructure to switch between volatile and non‐volatile RS behavior, which indicates a threshold RS and broadly increases its practical applicability. The stacks of Pt/PbZrO3 (PZO)/LaNiO3/SrTiO3 (STO) is fabricated by laser pulse deposition. It exhibits a tunable RS behavior from volatile to nonvolatile through adjusting voltage amplitude. Moreover, a high ON/OFF ratio, good retention, and endurance characteristics are achieved. Furthermore, synaptic behaviors related to neural learning functions in PZO film is explored, that is, long‐term potential/depression, spike timing dependent plasticity, and paired pulse facilitation. This work provides a way to engineer AFE and RS pertinent functionality for the low‐energy‐consumption, non‐volatile neural computing. [ABSTRACT FROM AUTHOR]

NASICON solid electrolyte Na3Zr2Si2PO12 (NZSP) exhibits high chemical stability and can be utilized as cladding materials of cathodes to improve battery cycle stability. However, the electronic conductivity of NZSP is extremely low (∼10−9 S cm−1), which will hinder the electron conduction of cathode materials. To address this issue, the electronic conductivity of NZSP is improved by doping with transition metal elements (Co, Fe, Ni). Co‐doped NZSP has an electronic conductivity of 5.03 × 10−6 S cm−1. On the other hand, the ionic conductivity of doped samples remains stable, even slightly increased. The mechanical properties of pristine and doped samples are characterized with a micro indenter, which is also a key parameter for coating materials. [ABSTRACT FROM AUTHOR]

The ternary cathode material LiNi0.83Co0.12Mn0.05O2 (NCM) has excellent properties, such as superior energy density, low cost, and high voltage platform. Recently, it becomes one of the research hotspots of lithium-ion batteries (LIBs). However, NCM has insufficient cycle stability and cannot meet the demand for the high-rate capability, which limits its application in energy storage equipment. The precursor of NCM was modified with (Ni0.4Co0.2Mn0.4)1−xZrx(OH)2 by the co-precipitation. After high-temperature sintering, the diffusion of Zr4+ has significant impacts on the stability and capability for NCM. The doped sample exhibits a capacity retention rate of 79.5% at 1 C after 200 cycles and also delivers excellent rate performance, and the average specific discharge capacity is 189.4 mAh g−1 (2 C) and 180.6 mAh g−1 (5 C), respectively. [ABSTRACT FROM AUTHOR]

Abstract: (Ba0.95Ca0.05)(Ti0.88Zr0.12)O3 (BCTZ) ceramics have been produced in a protective atmosphere of industrial N2 gas for potential piezoelectric applications. For comparison, the ceramics were also sintered at 1200–1400°C in air. The results revealed that the reducing atmosphere of pO2 =5×102 Pa had no substantial effect on the phase structure or the microstructure of the BCTZ ceramics. The XRD patterns suggested a tetragonal to pseudocubic phase transition at sintering temperatures above 1300°C in both atmospheres. The nitrogen-sintered BCTZ samples had higher dielectric constants ɛ r but lower electromechanical coupling coefficients k p than the air-sintered samples. The piezoelectric constant d 33 for the BCTZ ceramics was not significantly influenced by the reducing atmosphere of pO2 =5×102 Pa. The correlation of dielectric and piezoelectric properties of the BCTZ ceramics with the sintering temperature was explained based on a competing mechanism between phase structure and microstructure. [Copyright &y& Elsevier]

Bi 2 (TeSe) 3 is a dominant n-type thermoelectric material used in commercial applications. However, its toxicity and rarity hamper further large-scale industrial applications. Herein, we develop a Ag 8 SiSe 6 -based composite as a promising n-type semiconductor with the advantages of nontoxicity and elemental abundance. Ag 8 SiSe 6 composites with Ag 2 Se and Si nanoprecipitation are fabricated by a unique precipitation reaction sensitive to the hot pressing process. The energy-filtering effect between these phases optimizes electrical resistivity (∼14.59 μΩ·m) and the Seebeck coefficient (above -150 μV·K -1 ) of the composites, resulting in a maximum power factor of ∼1772 μW·m -1 ·K -2 (@125 °C), which is the highest value in an argyrodite system near room temperature. Nanoprecipitation of Ag 2 Se and Si can also scatter more phonons and further reduce the lattice thermal conductivity to 0.20 W·m -1 ·K -1 . As a result, a maximum ZT value of ∼0.9 (@125 °C) and an average ZT value of ∼0.7 (25-200 °C) are obtained in the composite with 12 vol % Ag 2 Se and 0.23 vol % Si, which is sintered at 525 °C. These thermoelectric properties are comparable to those of a commercial n-type Bi 2 Te 3 compound. In addition, the Ag 8 SiSe 6 composite has robust mechanical properties (Vickers hardness of >110 HV and bending strength of 70.6 MPa), much better than those of other thermoelectric compounds, because of which Ag 8 SiSe 6 has great commercial application as an alternative to Bi 2 Te 3 -based compounds.