9results about How to "Improve capacity play" patented technology

This invention relates to a method for improving the consistency of battery cell sorting based on DC internal resistance time-domain response subdivision. The method includes: performing a DC internal resistance test on the battery cells to be sorted, the DC internal resistance test including constant current discharge of the battery cells to be sorted, and collecting voltage and current time series data of the battery cells to be sorted during the constant current discharge process. A time reference is determined for the constant current discharge to reach a target current steady state, and multiple response time intervals are determined based on the time reference. Using the EIS principle, a reference voltage value before constant current discharge and the interval voltage value corresponding to each response time interval are determined. Multiple time-domain segmented equivalent impedance parameters of the battery cells to be sorted are calculated. The battery cells to be sorted are then sorted according to the multiple time-domain segmented equivalent impedance parameters. This method can improve the consistency of DC load response among battery cells in the same group and is beneficial for improving the capacity utilization, power output, temperature rise dispersion, and cycle aging consistency after battery cell grouping.

This application proposes a layered cathode material, its preparation method, and a lithium-ion battery. The layered cathode material includes a lithium source, a manganese source, and a grain refiner. By adding a grain refiner to the raw materials, the layered cathode material has a larger half-maximum width at half-maximum (FWHM) and a smaller grain size, or an I(010) / I(021) intensity ratio in the range of 0.3 to 0.85. This shortens the lithium-ion diffusion path, which is beneficial for lithium-ion diffusion, thereby improving the rate performance, capacity utilization, and cycle stability of the material. The layered cathode material of this application is a primary particle and a single-crystal material. Compared with conventional polycrystalline materials, single-crystal materials do not have the anisotropic stress problem of polycrystalline materials. The stress distribution of single-crystal materials is uniform, and the mechanical stress is stable. Therefore, it has less expansion stress and less volume deformation during charge and discharge, which can reduce the generation of particle cracks and effectively delay the occurrence of failure.

This invention relates to a Cr and Br dual-element doped polyanionic sodium-ion battery cathode material, sodium iron phosphate pyrophosphate, its preparation method, and its application, belonging to the field of sodium-ion battery technology. The general chemical formula of the cathode material of this invention is: Na₄Fe₂O₃. 3‑x Cr x (PO4)2P2O7Br y Where 0 < x < 0.5, 0 < y < 0.7; the precursor wet gel is obtained through a sol-gel process, dried, and then sintered. This invention relates to a Cr- and Br-doped polyanionic sodium-ion battery cathode material, sodium iron phosphate pyrophosphate. The Cr dopant enhances bulk stability, while the gradient distribution of Br forms a fast ion conduction layer on the surface. The two elements together improve the rate capability and cycle performance of the sodium-ion battery. This provides a modification strategy of significant reference value for cathode materials that suffer from low discharge specific capacity and poor cycle performance at high rates due to electron conductance differences.

This invention discloses a composite anode material for an all-solid-state lithium-ion battery, its preparation method, and the all-solid-state lithium-ion battery itself, relating to the field of all-solid-state lithium-ion battery technology. The composite anode material comprises a silicon skeleton and multiple functional coating layers sequentially covering the outer surface of the silicon skeleton. The pore size and porosity of the silicon skeleton gradually increase from the inside out. The multiple functional coating layers, from the inside out, sequentially include a carbon layer, an ion-conducting layer, and an interface protection layer, wherein the ion-conducting layer is a composite material of a sulfide solid electrolyte and a lithium-containing compound. The silicon skeleton of this invention has a non-uniform pore distribution. This pore distribution structure allows the loose outer layer of the skeleton to effectively absorb stress, thereby more effectively protecting the structural integrity of the core region. This application achieves a synergistic effect of stress buffering, ion transport, and interface stabilization through multiple functional coating layers, suppressing the possibility of silicon anode failure and effectively extending the cycle life of the battery.

The invention discloses a cylindrical battery and a power utilization device, and belongs to the technical field of new energy materials. By adopting an in-situ polymerization technology, a compact and continuous quasi-solid electrolyte network is constructed in the cylindrical roll core, so that the safety pain points that a traditional liquid lithium ion battery is easy to leak and inflammable and explosive are fundamentally solved, and meanwhile, the technical bottlenecks that a solid-solid interface of a solid-state battery is poor in contact and large in impedance are overcome; according to the battery system, atomic-scale close contact of the electrolyte and the electrode particles is realized, the intrinsic safety and the energy density of the battery are remarkably improved while high ionic conductivity is ensured, and the battery system is particularly suitable for the power and energy storage fields with extremely high safety requirements.

This invention provides a secondary battery comprising a positive electrode, a negative electrode, and an electrolyte layer, wherein: the negative electrode is composed of a conductive current collector, a negative electrode active material, and a non-alkali metal monovalent ion conductor; the secondary battery is a sodium secondary battery or a lithium secondary battery. The secondary battery of this invention, such as an alkali metal secondary battery, is more stable under environmental conditions, easier to manufacture, less expensive, has improved rate performance, and significantly increased cycle life.

This invention discloses an oil-based binder, anode slurry, a composite silicon anode, and an all-solid-state battery, belonging to the technical field of all-solid-state battery energy storage materials. The oil-based binder comprises component A and component B; component A is a copolymer composed of acrylate, long-chain ether oxygen bonds, and epoxy active groups, while component B is a styrene-ethylene-butene-styrene block copolymer. This binder is prepared through free radical polymerization and physical blending, is soluble in weakly polar solvents, and is suitable for composite silicon anode systems based on sulfide solid electrolytes. The binder provided by this invention possesses excellent ion conduction ability, mechanical properties, and interfacial adhesion, effectively buffering the volume expansion of the silicon anode, maintaining electrode structural stability and interfacial ion transport, thereby significantly improving the rate performance and long-cycle stability of the all-solid-state battery.

The application provides a method for preparing lithium manganese iron phosphate from iron hydroxyphosphate, wherein ferrous sulfate is purified to form a ferrous sulfate solution, hydrogen peroxide, phosphoric acid, ammonium dihydrogen phosphate solution, titanium sulfate and ammonia are sequentially added into the solution to form a mixed slurry after reaction, the mixed slurry is heated to a certain temperature and kept for a certain time, and then water washing and pressure filtration are performed to form iron hydroxyphosphate precursors with different iron-phosphorus ratios; the iron hydroxyphosphate precursors are subjected to flash drying and high-temperature sintering and crushing to obtain iron hydroxyphosphate precursors with different iron-phosphorus ratios and different specific surface areas; the iron hydroxyphosphate precursors are crushed and mixed to obtain iron hydroxyphosphate finished products; high-iron-phosphorus-ratio iron hydroxyphosphate and low-iron-phosphorus-ratio iron hydroxyphosphate are mixed according to a certain proportion, and lithium source, manganese source and phosphorus source are proportioned according to a certain proportion, and carbon source and additives are added to form a mixture; and after processes such as ball milling, sand milling, spray drying, sintering, crushing, screening, batching and packaging are performed on the mixture, lithium manganese iron phosphate finished products are obtained.

This invention relates to the field of sodium-ion battery technology, specifically disclosing a sodium-ion battery cathode material, its preparation method, a battery cell, and a battery. The cathode material involves the sequential stacking of single-crystal particles, near-single-crystal particles, and aggregated particles along a vertical direction from a foil substrate. The single-crystal particles are single, blocky crystals; the near-single-crystal particles are secondary particles formed by the stacking and connection of multiple single-crystal particles, which are mixed with and fill the gaps between the single-crystal particles; the aggregated particles are secondary particles formed by the stacking of multiple micro / nano particles, used to provide a rapid migration channel for ions at the cathode, shortening the ion migration distance and enabling fast charging of the sodium-ion battery. This invention involves the sequential stacking of three layers of three types of active particles—single-crystal particles, near-single-crystal particles, and aggregated particles—starting from the vertical direction of the foil substrate. This multi-gradient cathode material design greatly improves the space utilization and energy carrying capacity of the active material on the electrode, while also providing fast charging capability.