Core Performance Indicators of Lithium Battery Anode Materials

Core Performance Indicators of Lithium Battery Anode Materials

As the key composition of power batteries, what are the core performance indicators of lithium battery anode materials? The core performance indicators of lithium battery anode materials, including particle size, tap density, true density, discharge capacity, first efficiency, cycle performance, rate performance, etc.

Here's What These Performance Metrics Mean:

(1) Specific Surface Area (and particle size) : refers to the surface area of an object per unit mass. The smaller the particle, the larger the specific surface area. For the anode with small particles and high specific surface area, there are more channels and shorter paths for lithium ion migration, so the rate performance is better. However, due to the large contact area with electrolyte and the large area for forming SEI film, the first efficiency will also be lower.

(2) vibration Density: it is the mass of unit volume measured by vibration to make the powder present a relatively close accumulation form, and the unit is g/cm3.

(3) True Density: the weight of solid material per unit volume in absolute dense state (excluding internal void), in unit of g/cm3.

(4) The First Efficiency: after some lithium ions are removed from the positive electrode and embedded into the anode electrode, they cannot return to the positive electrode to participate in the charge-discharge cycle, resulting in the first charge-discharge efficiency is not 100%.

(5) Cycle Life and Expansion: There is a positive correlation between expansion and cycle life. After the expansion of the anode electrode, firstly, the core-winding deformation will be caused, the negative particles will form micro-cracks, and the SEI film will break and recombine, consume electrolyte, and the cycle performance will deteriorate. The second is that the diaphragm will be squeezed, especially at the right Angle edge of the polar ear of the diaphragm extrusion is more serious, easy to cause micro short circuit or micro metal lithium precipitation with the charge-discharge cycle.

(6) Rate Performance: the same as the cycle life and expansion, isotropic anode electrode, lithium ion transmission channels, to solve the anisotropic structure embedded in the emergence of less entrance, low diffusion rate, also has a role in the charge and discharge of large current.