A High-performance Lithium Metal Battery with a Multilayer Hybrid Electrolyte

Solid-state batteries have been considered as a good choice for substituting traditional batteries with liquid electrolytes because of their high energy density and safe property.However,a little amount of flammable non-aqueous liquid electrolyte or polymer electrolyte is usually required to improve the interfacial contact,which is adverse to safety.Here,a nonflammable gel is prepared by hydrogen-bond interaction and applied as an interfacial layer to improve the performance of solid-state batteries.The prepared multilayer hybrid electrolyte(MHE)composed of gel and CPE shows a wide electrochemical window(5.3 V vs Li/Li+),high ionic transference number(0.57),and ionic conductivity(7.18×10^(−4) S cm^(−1))at room temperature.Thus,the assembled Li symmetric cell with MHE can cycle over 650 h at 0.5 mA cm^(−2) with a lower overpotential of~61 mV.The LiFePO_(4)|MHE|Li cell exhibits a higher discharge capacity of 107.8 mAh g−1 even cycled at 5 C.It also shows superior capacity retention of 96.4%after 1000 cycles at 0.5 C.This work provides a promising strategy for designing high-performance solid-state batteries.

TWrist:An agile compliant 3-DoF tensegrity joint

Tensegrity structures,with their unique physical characteristics,hold substantial potential in the field of robotics.However,the very structures that will give tensegrity robots potential advantages over traditional robots also hold long term challenges.Due to the inherent high redundancy of tensegrity structures and the employment of tension elements,tensegrity robots exhibit excellent stability,compliance,and flexibility,although this also results in lower structural deformation efficiency.Existing research has endeavoured to enhance the motion performance of tensegrity robots,exploring diverse approaches such as actuation schemes,structure design,aligned with control algorithms.However,the physical constraints of the elements in such structures and the absence of suitable controllers impede further advancements in the usefulness of tensegrity robots.This paper presents a novel design based on an under constrained transition region design and a tailored control approach based on inverse kinematics,improving the motion performance of the proposed novel tensegrity joint.Through this approach,the tensegrity joint,while preserving the advantages of compliance and flexibility expected from tensegrity structures,offers three degrees of rotational freedom,mirroring the controllability of conventional rigid-body joints.The results demonstrate the capability of tensegritybased robotic joints to provide flexible actuation under situations demanding high compliance.The integration of structure design with a tailored control approach offers a pioneering model for future development of tensegrity robots,underscoring the practical viability of tensegrity structures in the realm of robotics.

Efficient single-component white light emitting diodes enabled by lanthanide ions doped lead halide perovskites via controlling Forster energy transfer and specific defect clearance

Currently,a major challenge for metal-halide perovskite light emitting diodes(LEDs)is to achieve stable and efficient white light emission due to halide ion segregation.Herein,we report a promising method to fabricate white perovskite LEDs using lanthanide(Ln^(3+))ions doped CsPbCl_(3) perovskite nanocrystals(PeNCs).First,K^(+)ions are doped into the lattice to tune the perovskite bandgap by partially substituting Cs^(+)ions,which are well matched to the transition energy of some Ln^(3+)ions from the ground state to the excited state,thereby greatly improving the Förster energy transfer efficiency from excitons to Ln3+ions.Then,creatine phosphate(CP),a phospholipid widely found in organisms,serves as a tightly binding surface-capping multi-functional ligand which regulates the film formation and enhances the optical and electrical properties of PeNC film.Consequently,the Eu^(3+)doped PeNCs based-white LEDs show a peak luminance of 1678 cd m^(-2) and a maximum external quantum efficiency(EQE)of 5.4%,demonstrating excellent performance among existing white PeNC LEDs from a single chip.Furthermore,the method of bandgap modulation and the defect passivation were generalized to other Ln^(3+)ions doped perovskite LEDs and successfully obtained improved electroluminescence(EL).This work demonstrates the comprehensive and universal strategies in the realization of highly efficient and stable white LEDs via single-component Ln^(3+)ions doped PeNCs,which provides an optimal solution for the development of low-cost and simple white perovskite LEDs.

Eu^(3+)-Bi^(3+)Codoping Double Perovskites for Single-Component White-Light-Emitting Diodes

Double perovskites(DPs)with Cs_(2)AgInCl_(6) composition,as one of the lead-free perovskites,have been in the spotlight owing to their intriguing optical properties,namely,self-trapped exciton(STE)emission and dopant-induced photoluminescence.However,the current DPs still face the challenge of low photoluminescence efficiency and cannot be applied in practice.Herein,we synthesize the Bi^(3+)and Eu^(3+)codoped Cs_(2)AgInCl_(6) DPs,which displays enhanced STE and Eu^(3+)ions characteristic emissions.Our results indicate that the Eu^(3+)ions mainly substitute the In sites and can increase the radiative recombination rate and exciton binding energy of STEs,which is discovered that Eu^(3+)ions can promote the localization of STEs by breaking the inversion symmetry of the Cs_(2)AgInCl_(6) lattice.The existence of Bi^(3+)ions decreases the excitation(absorption)energy,provides a new absorption channel,and increases the energy transfer rate to Eu^(3+)ions.Through adjusting the Bi^(3+)and Eu^(3+)concentrations,a maximum photoluminescence quantum yield of 80.1%is obtained in 6%Eu^(3+)and 0.5%Bi^(3+)codoped Cs_(2)AgInCl_(6) DPs.Finally,the high-quality single-component white-light-emitting diodes based on Bi^(3+)and Eu^(3+)codoped Cs_(2)AgInCl_(6) DPs and a 410-nm commercial ultraviolet chip are fabricated with the optimum color rendering index of 89,the optimal luminous efficiency of 88.1 lm/W,and a half-lifetime of 1,493 h.This work puts forward an effective lanthanide and transition metals codoping strategy to design single-component white-light emitter,taking a big step forward for the application lead-free DPs.