Li-Ion Cell Operation at Low Temperatures

Abstract

Substantially reduced energy and power capabilities of lithium-ion cell operating at low temperatures pose a technical barrier for market penetration of hybrid electric vehicles and pure electric vehicles. The present work delineates Li-ion cell behaviors at low temperatures by a combined experimental and modeling approach. An electrochemical-thermal coupled model, incorporating concentration-and temperature-dependent transport and kinetic properties, is applied and validated against 2.2Ah 18650 cylindrical cells over a wide range of temperatures (−20 • C to 45 • C) and discharge rates. Simulation and experimental results demonstrate the dramatic effects of cell self-heating upon electrochemical performance. A nonisothermal Ragone plot accounting for these important thermal effects is proposed for the first time for Li-ion cells and more generally for thermally coupled batteries. Detailed resistance analysis indicates that performance limits at −20 • C depend on not only discharge rates but also thermal conditions. Optimization of cell design parameters and material properties is performed for 1 C rate discharge starting from −20 • C, where the principal performance limitations are found to be Li + diffusion in the electrolyte and solid-state Li diffusion in graphite particles, instead of charge-transfer kinetic or ohmic resistance.

Disordered Lithium‐Rich Oxyfluoride as a Stable Host for Enhanced Li+ Intercalation Storage

“…These results confirmed again a fast kinetic behavior for the Li 2 VO 2 F. In contrast, by decreasing the temperature from 25°C to -10°C, LiFePO 4 [27] and LiNi 1/3 Mn 1/3 Co 1/3 O 2 [28] cathode materials showed relatively large increase in polarization with a discharge voltage shifted down by ~0.3 V.…”

Radially aligned hierarchical columnar structure as a cathode material for high energy density sodium-ion batteries

“…The delivered capacities of the cell reached 143 mAh g À 1 at 30°C, 147.6 mAh g À 1 at 55°C and 128.8 mAh g À 1 at 0°C. The capacity decreases to 114 mAh g À 1 at À 20°C; however, this value is still sufficiently high compared with Li cells [45][46][47] . At 30°C, the average operation voltage is found to be 2.84 V on discharge.…”

Evaluation of Model Based State of Charge Estimation Methods for Lithium-Ion Batteries

“…There are plenty of battery models reported in previous studies, including physics-based models and equivalent circuit models. Physics-based models [26][27][28], could be full order models, simplified reduced order models, single particle models and so forth, while the equivalent models could be the first order RC model [29], the second order RC model [29,30], the impedance model [20], etc. However, the Li-ion battery is a complex electrochemical system, which can show strong nonlinearity and uncertainty.…”