LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) became a research hot point because of its low cost, environmental friendliness, and excellent electrochemical performance. However, Li⁺/Ni²⁺ intermixing is an essential factor affecting its applicability. Doping could be an important method to improve the electrochemical performance of NCM811-based cathode materials. In this work, La and Al co-doped NCM811 was prepared by a solid-state method. Results from X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) and electrochemical performance were discussed in depth. These showed that when La and Al doping concentrations were 1 and 0.5%, the samples showed the best performance. The as-improved performances were mainly attributed to the reduced Li⁺/Ni²⁺ intermixing, suppressed phase transition, and decreased potential polarization and impedance.

To achieve high dynamic range performance in X-ray streak cameras and precision diagnostics, the theory of post-acceleration internal gain technology in streak cameras is investigated from photon density detection threshold. The reduction of threshold limited by system sensitivity is beneficial for expanding the dynamic range. The streak camera incorporating post-acceleration internal gain technology is designed and an ultra-fast laser calibration system is established. Experiments show that the camera's dynamic range reaches 2 578∶1. Compared to microchannel plate internal gain technology with the saturation effects, the technology significantly expands the dynamic range performance. The nonlinear sources of signal intensity on the screen are identified by the different transmittance of electrons with different directional angles, and the intensity error distribution in the imaging area and its correction methods are provided. The dynamic range error is 7.7% compared with the uncorrected one. The system structure of the post-acceleration internal enhancement technology is compact, which is conducive to improving the dynamic range of the streak camera, and helps to realize the goal of quantitative measurement and precision diagnosis of laser driven inertial confinement fusion in China.

We present a single-shot ultrafast imaging technique named wavelength /polarization-time encoded ultrafast raster imaging (WP-URI). This innovative method harnesses the principles of raster imaging in conjunction with wavelength and polarization time encoding to achieve high frame rate, high spatial resolution imaging at the atomic time scale (10 femtoseconds to 1 picosecond). The WP-URI system employs four femtosecond laser pulses, each with distinct wavelengths and polarizations, to illuminate and capture ultrafast events. These events are subsequently sampled by a spatial sampling mask and imaged to record the wavelength/polarization-encoded raster images in a single exposure. Through numerical simulations, we demonstrate the system's capability to image uniformly moving objects and rotating sector-shaped objects at an unprecedented frame rate of 25 trillion frames per second (Tfps), with an intrinsic spatial resolution of 50 line-pairs per millimeter(lp/mm), capturing four frames in a single exposure on a femtosecond timescale, and accommodating a large imaging area. With the advantages of both high spatio-temporal resolution and high frame rate, the WP-URI system has become a powerful tool for studying the interactions of matter and carrier dynamics in plasma physics, femtosecond lasers, and semiconductor devices.

This paper introduces a single-shot ultrafast imaging technique termed wavelength and polarization time-encoded ultrafast raster imaging (WP-URI). By integrating raster imaging principles with wavelength- and polarization-based temporal encoding, the system uses a spatial raster mask and time–space mapping to aggregate multiple two-dimensional temporal raster images onto a single detector plane, thereby enabling the effective spatial separation and extraction of target information. Finally, the target dynamics are recovered using a reconstruction algorithm based on the Nyquist–Shannon sampling theorem. Numerical simulations demonstrate the single-shot acquisition of four dynamic frames at 25 trillion frames per second (Tfps) with an intrinsic spatial resolution of 50 line pairs per millimeter (lp/mm) and a wide field of view. The WP-URI technique achieves unparalleled spatio-temporal resolution and frame rates, offering significant potential for investigating ultrafast phenomena such as matter interactions, carrier dynamics in semiconductor devices, and femtosecond laser–matter processes.