Cold Temperature Charge / Discharge

What are the Cold Temperature Charge / Discharge limitations and mechanisms?

cell capacity versus temperature

At cold temperatures lithium ion cells suffer from a significant decrease in available capacity.

DCIR of a Panasonic 18650 3.2Ah cell

The DCIR of the cell increases significantly as the temperature decreases. Significantly reducing the available peak and continuous power.

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Luo et al [1] describe the reasons for poor performance in cold temperatures as:

  1. poor kinetics on both the interphase and the electrodes, which means larger SEI resistance and a reduction in the Li+ diffusion coefficient in the cathode and anode
  2. decreased ionic and electronic conductivity, lower viscosity, and high freezing point of the electrolyte
  3. lithium plating and Li dendrites on the surface of the anode, which threaten the safety and cycle life of LIBs.

The lithium-ion battery consists of a lithium compound-based cathode, carbon-based anode, an electrolyte and a separator. The cathode materials are coated onto an aluminum foil and the anode materials are coated ont a copper foil, both foils serving as the current collectors. A porous polymer separator stops an electrical short between the anode and cathode, but allows lithium-ions to pass through. This stack is immersed in electrolyte. Lithium ions go through the cycles of intercalation and deintercalation, and move through the electrolyte as charge carriers in the internal circuit. With the intercalation and deintercalation of lithium ions, redox reactions occur at the electrodes, which generate electrons that move directionally through the external circuit to form the current.

Hence, we need to look at the components in the stack.

Cathode

Degradation of the cathode at low temperature is mainly due to the decreased Li+ diffusion coefficient and high charge transfer resistance caused by low kinetics, leading to significantly increased polarization. These problems impede the (de)lithiation process, incurring certain energy and capacity loss

Anode

The low temperature performance depends more on the (de) intercalation kinetics on the anode surface. At low temperature, anodes are restricted with

  • low electronic and ionic conductivities
  • poor Li+ diffusion ability
  • increased charge transfer resistance
  • limited desolvation kinetics

The more serious problems are the lithium plating and lithium dendrites occurring at the anode.

Electrolyte

Below 0 °C, the viscosity of the electrolyte increases while the Li+ conductivity decreases, limiting the process of Li+ diffusion.

The low-temperature restriction of Li+ transport in the electrolyte is much larger than that in the electrode.

At the electrode–electrolyte interface the wettability and compatibility of the viscous electrolyte with respect to the electrode and separator become worse, increasing the resistance of LIBs, while a thicker SEI on the anode side hinders transport on the interface, as well as the desolvation process.

electrolyte conductivity versus temperature

Evan M. Erickson et al [4] show how the conductivity of the electrolyte increases with temperature.

The difference in conductivity of the electrolyte between -20°C and 20°C can be 4x higher.

Improving Cold Temperature Performance

The standard approach to improving the cold temperature performance of a battery pack is to insulate the cells and to provide heating [3]. Some packs also use a carfeully managed discharge to gradually heat the cells.

Cell internal heating elements have also been proposed.

The longer term research and development direction is to improve the fundamental design of the chemistry and structure of the cell. There are a number of options already used to improve the conductivity of the cathode and anode. Also, additives are already used to improve the electrolytes. Lu et al [2] propose an electrolyte that results in good cycling performance even at -65°C.

References

  1. Luo H, Wang Y, Feng YH, Fan XY, Han X, Wang PF. Lithium-Ion Batteries under Low-Temperature Environment: Challenges and Prospects. Materials 202215(22), 8166
  2. Lu, D., Li, R., Rahman, M.M. et al. Ligand-channel-enabled ultrafast Li-ion conductionNature 627, 101–107 (2024)
  3. Gong Cheng, Zhangzhou Wang, Xinzhi Wang, Yurong He, All-climate thermal management structure for batteries based on expanded graphite/polymer composite phase change material with a high thermal and electrical conductivity, Applied Energy, Volume 322, 2022
  4. Evan M. Erickson, Elena Markevich, Gregory Salitra, Daniel Sharon, Daniel Hirshberg1, Ezequiel de la Llave, Ivgeni Shterenberg, Ariel Rosenman, Aryeh Frimer and Doron Aurbach, Review—Development of Advanced Rechargeable Batteries: A Continuous Challenge in the Choice of Suitable Electrolyte Solutions, Journal of The Electrochemical Society, Volume 162, Number 14

1 thought on “Cold Temperature Charge / Discharge”

  1. Don’t think I’ve ever seen an off-the-shelf lithium battery with as bad cold-weather performance as the one in that image. Maybe that’s the battery they use in iPhones. 😂

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