Fast‐charging and high‐energy‐density solid‐state sodium metal batteries (SMBs) working under harsh temperatures are in urgent demand for the state‐of‐the‐art secondary batteries. However, the ...unmatched interfacial contact and temperature‐limited ionic conductivity still impede SMBs from authentic commercialization. Constructing a 3D ion diffusion channel through in situ interlock interfaces can effectively address these bottlenecks. Herein, an in situ cured gel polymer electrolyte (GPE) is developed by introducing trihydroxymethylpropyl triacrylate (TMPTA) into conventional electrolytes. The as‐prepared GPE can generate superior 3D ionic conductive networks in the cathodes with high ionic conductivity at universal temperatures (0–60 °C) and a wide working potential, which successfully pairs with the high‐voltage cathodes with ultrahigh loads of 13.01 mg cm−1 to develop a practical solid‐state battery. Furthermore, as deciphered by in‐depth X‐ray photoelectron spectroscopy, the flexible solid electrolyte interphase layer is stable enough to prevent sodium metal from the corrosion of the electrolyte and the formation of sodium dendrites. Benefitting from this “two‐in‐one” effect, solid‐state SMBs with the in situ GPE exhibit an excellent long‐term cycling stability at 60 °C with a capacity retention of 80% after 1000 cycles at 1 C, and superior temperature adaptability even at 0 °C with a rate capacity retention of 90% at 1 C compared with that at 0.1 C.
Herein, a gel polymer electrolyte (GPE) is designed to develop practically accessible and environmentally adaptive sodium metal batteries (SMBs) with high loading cathodes through in situ interlock interface. The GPE‐based SMBs exhibit superior temperature adaptability at 0–60 °C, fast rate capability up to 30 C, and successfully pairs with ultrahigh cathode loads of 13.01 mg cm−2.
•The QDFrHT is proposed to generalize the discrete fractional Hartley transform into quaternion transform domain.•A large-capacity image compression and encryption scheme based on QDFrHT and an ...improved adaptive pixel diffusion is developed.•The storage and transmission of the keys are more convenient due to small key consumption.•Secret keys utilized in the proposed scheme are independent to original images.•An improved adaptive pixel diffusion operation makes the proposed cryptosystem immune to the known-plaintext attack and the chosen-plaintext attack.
A new multi-image encryption scheme based on quaternion discrete fractional Hartley transform (QDFrHT) and an improved pixel adaptive diffusion is proposed, which can simultaneously increase the encryption capacity and reduce the consumption of keys. In the proposed scheme, the QDFrHT is proposed to generalize the discrete fractional Hartley transform to quaternion transform domain and then applied to multi-image encryption. The original images are compressed into four fusion images by discrete cosine transform (DCT) and Zigzag operations and then the resulting four images are represented as quaternion algebra. Afterward, the quaternion signal is processed with the proposed QDFrHT and the double random phase encoding technique. To enhance the security of the algorithm, the plaintext-related pixel adaptive diffusion and the pixel scrambling operation based on chaotic systems are followed to obtain the final encryption image. Different from the traditional cryptosystem whose secret keys are dependent on the plaintext, the designed cryptosystem ensures the sensitivity of the cryptosystem to plaintext while the selection of the secret keys is independent on plaintext by introducing an improved diffusion mechanism. Numerical experiments verify the feasibility and the efficiency of the proposed multi-image compression and encryption scheme.
Li-metal batteries have been emerging as attractive technologies for electrical energy storage and conversion by virtue of the ultrahigh theoretical specific capacity of lithium. However, the ...undesirable Li-dendrite growth upon prolonged cycling gives rise to thermal runaway, inducing tremendous safety concerns that impede the development of the technology. In general, Li nucleation and growth behavior significantly changes when the operating condition is modified through modulating temperature or thermodynamic energy to produce regulated lithium depositions. Herein, this perspective takes these two key factors as an example to emphasize the importance of thermodynamic understandings of the Li-dendrite issue. The key challenges and corresponding strategies for designing advanced dendrite-free Li-metal anodes with respect to thermodynamic factors are also discussed as fundamental guidance for future development.
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The recent boom in electrical energy storage and conversion with high-energy density facilitates the exploration of Li-metal batteries. However, Li dissolution and nucleation are easily susceptible to thermodynamic conditions that induce dendrite growth, causing tremendous safety hazards, low energy density, and short lifespan. Nevertheless, a comprehensive understanding of the thermodynamic effects on lithium deposition and growth is still absent.
The development and latest research progress of thermodynamic-inducing factors regarding lithium nucleation and growth are systematically summarized from theory to experiment, especially focusing on thermodynamic energy, temperature, and related models. Strategies for designing a dendrite-free Li-metal anode through thermodynamic considerations, including structured anode, self-healing dendrite tactics, and electrode and electrolyte interface engineering are also discussed. We highlight the imperfections of present thermodynamic research and propose corresponding feasible solutions. Future work should evaluate each individual system on its own to integrate suitable models that combine with kinetics and other factors to find interrelated strategies to address the dendrite-growth issues under various conditions.
Li dissolution and nucleation are easily susceptible to thermodynamic conditions that induce dendrite growth, giving rise to thermal runaway and causing tremendous safety hazards. Here, Gao et al. systematically summarize the progress in thermodynamic effects on lithium formation from theory to experiment and highlight the imperfections of present thermodynamic research as well as propose corresponding feasible solutions. This review provides a fundamental guidance for future development of dendrite-free Li-metal anodes.
Practical lithium metal batteries (LMBs) are still far from market readiness, as a result of the severe Li degradation and safety issues caused by Li dendrites. Herein, by studying the thermodynamic ...behavior of lithium deposition, it is unveiled that the tip area of Li metal has an increasing heat generation rate as a function of the deposition time and overpotential. This triggers the emergence of the accumulated overpotential heat and local temperature “hotspots” due to poor local thermal diffusion, which exacerbates the undesirable irregular Li deposition and dendrite growth. To address this issue, a thermally conductive graphene‐coated separator is constructed to eliminate these local hotspots. The graphene layer affords timely diffusion of local heat generated by irregular Li growth and incipient dendrite formation, achieving the stable and uniform lithium deposition to deter further degradation. As a result, the Li metal, suffering a drastic Coulombic efficiency (CE) decay to ≈60% using a conventional separator, can be recovered for continual cycling with a high CE of >95%. Notably, the corresponding Li||LiNi0.8Mn0.1Co0.1O2 cells present high capacity retention and recovery. This study highlights the thermodynamic factor of Li dendrite‐induced local heat and its elimination to preclude Li anode deterioration, which provides insight into Li metal protection strategies for high performance LMBs.
The formation of local temperature “hotspots” is demonstrated to be one of the triggers for dendritic lithium evolution by a thermal–electrochemical coupling simulation. To eliminate the “hotspots”, a graphene‐layer‐coated thermal conductive separator is constructed to achieve homogeneous lithium deposition and even “recover” cycled undesirable lithium deposition, leading to a superior electrochemical performance paired with NCM811 cathode under a loading of 30 mg cm−2 and N/P ratio of 3.3.
The application of semi‐quantum conception can provide unconditional secure communication for communicators without quantum capabilities. A semi‐quantum key distribution (SQKD) protocol based on ...four‐particle cluster states is put forward, which can achieve key distribution among one quantum party and two classical parties simultaneously. Furthermore, this protocol can be expanded to the χ‐party (χ>3) communication scheme. Compared with the existing multi‐party SQKD protocol, the proposed protocol and the extended one own more excellent time efficiency and qubit efficiency. The security of the proposed SQKD protocol under ideal circumstances is validated while the key rate under non‐ideal conditions is calculated.
The proposed semi‐quantum key distribution protocol with four‐particle cluster states can achieve key distribution among one quantum party and two classical parties simultaneously, which can be expanded to more than two classical communication parties. The proposed protocol owns great time efficiency and qubit efficiency, whose security under ideal circumstances and key rate under non‐ideal conditions are analyzed.
AbstractA fuzzy analytical hierarchy process (FAHP) is an effective risk assessment method in which a questionnaire is used to collect experts’ responses. However, determining fuzzy numbers and ...establishing a consistent judgment matrix are difficult in the FAHP. This study proposes a new consulting process for solving the previously mentioned problems in the triangular FAHP. The proposed consulting process consists of a newly designed questionnaire and a new approach for determining fuzzy numbers. Experts’ responses collected from the questionnaire are employed to determine fuzzy numbers and establish a consistent judgment matrix. The proposed method has been applied to the Jinan metro tunnel construction to demonstrate its validity. Both the traditional questionnaire and the new questionnaire are used to establish the judgment matrix in the case study. The results show that the judgment matrix determined from the new questionnaire can determine triangular fuzzy numbers and establish a consistent judgment matrix. Compared with the traditional questionnaire, the proposed questionnaire can be used to collect experts’ opinions with greater convenience and in less time.
To date, significant efforts have been dedicated to improve their ionic conductivity, thermal stability, and mechanical strength of solid polymer electrolytes (SPEs). However, direct monitoring of ...physical and chemical changes in SPEs is still lacking. Moreover, existing thermosetting SPEs are hardly degradable. Herein, by overcoming the limitation predicted by Flory theory, self‐reporting and biodegradable thermosetting hyperbranched poly(β‐amino ester)‐based SPEs (HPAE‐SPEs) are reported. HPAE is successfully synthesized through a well‐controlled “A2+B4” Michael addition strategy and then crosslinked it in situ to produce HPAE‐SPEs. The multiple tertiary aliphatic amines at the branching sites confer multicolour luminescence to HPAE‐SPEs, enabling direct observation of its physical and chemical damage. After use, HPAE‐SPEs can be rapidly hydrolysed into non‐hazardous β‐amino acids and polyols via self‐catalysis. Optimized HPAE‐SPE exhibits an ionic conductivity of 1.3×10−4 S/cm at 60 °C, a Na+ transference number (
tNa+
${{t}_{Na}^{+}}$
) of 0.67, a highly stable sodium plating‐stripping behaviour and a low overpotential of ≈190 mV. This study establishes a new paradigm for developing SPEs by engineering multifunctional polymers. The self‐reporting and biodegradable properties would greatly expand the scope of applications for SPEs.
Despite the significant effort to improve the performance of solid polymer electrolytes (SPEs), direct monitoring of physical and chemical changes as well as the sustainability in SPEs is still lacking. Here, we report a self‐reporting and biodegradable thermosetting SPE via well‐designed structure to analyze the performance mechanism behind SPEs and promote their environmental friendliness.
•An optical image encryption algorithm with phase-truncation in the short-time FrFT domain is proposed.•The wave-based permutation makes the phase part confused in the encryption unit.•The sub-images ...obtained by decomposing the original image is encoded with the encryption unit.
To increase the robustness against common attacks, a novel image encryption algorithm is proposed based on the phase-truncated short-time fractional Fourier transform (PTSTFrFT) and the hyper-chaotic system. In the algorithm, the original image is divided into four sub-images to be encoded independently. Different from the traditional phase truncation coding, the PTSTFrFT is combined with wave-based permutation to construct the encryption unit (EU) for encoding the sub-images, where the confused phase information is recombined with the amplitude information to guarantee the integrity of image information and the nonlinearity of phase truncation. Besides, the encryption unit can be achieved optically. Furthermore, the corresponding results compose an interim image, whose pixel values and pixel positions are modified by the permutation and the diffusion operations. The diffusion operation is designed with the feedback system to increase the anti-interference ability. The proposed image encryption algorithm has large enough key space and high sensitivity to the keys because of the use of hyper-chaotic system. The simulation results demonstrate that the proposed image encryption algorithm based on the PTSTFrFT is secure and robust enough against the common attacks.
To promote sustainable development, the Chinese government launched a new municipal solid waste (MSW) classification strategy in 2017. Shanghai was selected as one of the first pilot cities for MSW ...classification. The Shanghai municipal government first established the new MSW classification policy in 2017. The Shanghai Municipal Solid Waste Management Regulation was published in 2019 and came into effect on 1 July 2019. This short communication reports on Shanghai's new MSW classification policy and its implementation. The main content and measures adopted by Shanghai's government to ensure the effective implementation of the new MSW classification policy are introduced. Besides, a SWOT (i.e., strengths, weaknesses, opportunities, and threats) analysis on the present policy and measures is conducted, and based on the results, some discussions and suggestions regarding the implementation of MSW classification in Shanghai and the whole of China are presented.
•The discrete fractional Tchebyshev transform is extended to the QDFrTMT.•The QDFrTMT with quaternion symplectic form enhances the computational efficiency.•Sine-logistic exponential chaotic map and ...piece-wise linear chaotic map are cross-coupled.•Double layers permutation-diffusion operations are performed for better robustness.
With quaternion theory, the traditional discrete fractional Tchebyshev transform is extended to the quaternion algebra domain for multi-image processing. A new multi-image encryption scheme based on quaternion discrete fractional Tchebyshev moment transform (QDFrTMT) and the cross-coupling chaotic system is suggested. The original images are first confused by fractal sorting square matrix and sine-logistic exponential chaotic map, and then the resulting image is divided into four matrices. With the quaternion symplectic form representation, a quaternion signal can be formed by the divided matrices, which can reduce the number of the discrete fractional Tchebyshev transforms used and enhance the computational efficiency. Subsequently, the quaternion array is encrypted with the proposed QDFrTMT. To overcome the weakness of the permutation-diffusion operation based on a single chaotic map, a Logistic-sine exponential chaotic map and a piece-wise linear chaotic map are cross-coupled. The final ciphertext images can be acquired by carrying out the dual-layer encryption processes in horizontal and vertical directions. Numerical simulations and security analyses verify the effectiveness of the multi-image encryption algorithm and its strong ability to counteract common attacks.
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