How does lithium iron phosphate battery capacity fade?

As a key issue of electric vehicles, the capacity fade of lithium iron phosphate battery is closely related to solid electrolyte interphase growth and maximum temperature. In this study, a numerical method combining the electrochemical, capacity fading and heat transfer models is developed.

What is the electrochemical model of lithium iron phosphate battery?

Based on the pseudo two-dimensional (P2D) model of Doyle and Newman [ 32], the electrochemical model of lithium iron phosphate battery is developed in this paper, where the porous electrode theory, Ohm’s law, concentrated solution theory, solid-liquid diffusion process of lithium ion and electrode kinetics are all considered.

What are the mechanisms of capacity degradation of lithium ion batteries?

As well known, the main mechanisms of capacity degradation of li-ion batteries consist of lithium metal deposition, anodic oxidation and cathode reduction of electrolyte, formation of passive film on the surface of positive and negative electrodes, phase transformation and structural change of electrodes active materials, etc [, , , ].

Does charging rate affect lithium iron phosphate battery capacity?

Ouyang et al. systematically investigated the effects of charging rate and charging cut-off voltage on the capacity of lithium iron phosphate batteries at −10 ℃. Their findings indicated that capacity degradation accelerates notably when the charging rate exceeds 0.25 C or the charging cut-off voltage surpasses 3.55 V.

What is the battery capacity of a lithium phosphate module?

Multiple lithium iron phosphate modules are wired in series and parallel to create a 2800 Ah 52 V battery module. Total battery capacity is 145.6 kWh. Note the large, solid tinned copper busbar connecting the modules together. This busbar is rated for 700 amps DC to accommodate the high currents generated in this 48 volt DC system.

What happens when a lithium ion battery discharges?

When the lithium-ion battery discharges, its working voltage always changes constantly with the continuation of time. The working voltage of the battery is used as the ordinate, discharge time, or capacity, or state of charge (SOC), or discharge depth (DOD) as the abscissa, and the curve drawn is called the discharge curve.