The Non-Linear Voltammetry (NLV) charging method differs from Constant Current (CC) based charging methods in that no CC is applied at any time. Instead, a series of short Constant Voltage (CV) steps are applied, separated with very short rest periods while monitoring the current response and temperature. A transition from one CV plateau to the next occurs according to the current response [1].
Li and Yazami [1] performed tests on three different lithium-ion cells and clearly showed that NLV charging outperforms CC-based charging especially when the charging time falls below 20 minutes. NLV charging should become the preferred technology especially in electric vehicle applications where the charging time is crucial.
This adaptive charging method is described by Bandara and Yazami [2]:
NLV method consists of applying a charging protocol in a “loop” scheme in which the factors such as current, voltage, state-of-charge (SOC) and state-of-health (SOH) of a battery interactively contribute to the charging pattern at every step and finally to the resulting charging time. These factors contribute both directly and indirectly to varying, non-linearly controlled, set-voltage steps to charge the battery. The duration of these steps kept very short and dynamic throughout the entire charging process to self adjust its steps based on the changes of the aforementioned factors at a finer granularity. As such, the voltage increment at each charge step will depends on the SOC, SOH and the drawn current of the battery during its previous step.
The charging performance is significant and it should be noted that this can be applied across the 0 to 100% SoC window.
Their results show that two cells fast charged using CCCV in 30 minutes had brutal endings.
This is an interesting approach and shows the benefit of an adaptive charging protocol and rest periods that are used to acquire status data. These rest periods also allow both electrical and thermal redistribution within a cell.
This post has been built based on the support of and sponsorship from: Quarto Technical Services, Eatron Technologies and About:Energy
References
- Li, Shiqi and Yazami, Rachid, Reverse Ragone vs. Direct Ragone plots: a comparative study for ultra-fast charging lithium-ion batteries, EES Batteries, 2025
- Thusitha Asela Bandara and Rachid Yazami, Adaptive Charging Protocol (ACP) based on Non-linear Voltammetry (NLV) Charging Patterns for Fast charging Li-Ion batteries, International Journal of Engineering Science Invention (IJESI) ISSN (Online): 2319 – 6734, ISSN (Print): 2319 – 6726 www.ijesi.org ||Volume 7 Issue 12 Ver. III || Dec 2018 || PP 44-58