3results about How to "Improve capacity stability" patented technology

The invention relates to the technical field of sodium metal negative electrodes, in particular to a sodium metal negative electrode self-supporting material and a preparation method and application thereof. According to the preparation method of the sodium metal negative electrode self-supporting material, commercial carbon cloth is subjected to ultrasonic cleaning and drying and then is treated in a plasma treatment machine under atmospheric pressure, and the sodium metal negative electrode self-supporting material is obtained. According to the invention, the carbon cloth is treated through atmospheric pressure plasmas for the first time, high electronegativity elements such as N and O are introduced to the carbon cloth to improve the sodium affinity of the carbon cloth, and the carbon cloth is used as a self-supporting material of a sodium metal negative electrode. The carbon cloth subjected to plasma treatment shows lower nucleation overpotential for sodium metal, and a symmetrical battery assembled by a sodium metal negative electrode shows better electrochemical performance, has smaller voltage distribution and is more stable in operation. The total battery assembled by matching the sodium metal negative electrode with the sodium vanadium phosphate positive electrode has higher initial capacity, smaller polarization and better capacity stability.

The application relates to a high-nickel cobalt-free positive electrode material and a preparation method and application thereof. 1‑x‑y Fe x Mn y O2‑Ce&Cr@CeO2; the high-nickel cobalt-free positive electrode material comprises a positive electrode material LiNi 1‑x‑y Fe x Mn y O2 and a surface-coated CeO2 layer; wherein 1-x-y>0.8, 0.05<=x<=0.15, 0.05<=y<=0.15; the doping concentration of Ce and Cr elements is independently 0.5mol%-3mol%. The prepared high-nickel cobalt-free positive electrode material is applied to the field of lithium ion batteries, enhances lithium ion storage capacity and structural stability, reduces transition metal dissolution, reduces internal polarization resistance of the material, and exhibits excellent cycle stability and rate performance.

This invention discloses a Y-Sm-Mg-Ni hydrogen storage alloy electrode material and its preparation method. The chemical formula of the electrode material is Y 1‑a‑b Sm a Mg b Ni x Al y Where a, b, x, and y are atomic ratios, with 0.05 ≤ a ≤ 0.15, 0 ≤ b ≤ 0.2, 2.85 ≤ x ≤ 3.05, and 0 ≤ y ≤ 0.2. The preparation method involves using elemental metals, Y-Ni, and Mg-Ni master alloys as raw materials, and preparing the as-cast alloy using conventional induction melting. The as-cast alloy is then encased and sealed in a quartz tube under argon pressure of -0.09 to -0.05 MPa using tantalum sheets, and subsequently annealed in a muffle furnace. This invention significantly improves the cycle stability of Y-Mg-Ni alloys through Sm doping, and the preparation method reduces the preparation cost of Y-Sm-Mg-Ni alloys by using Y-Ni and Mg-Ni master alloys as raw materials.