Science & Technology (Commonwealth Union) – The fast-charging degradation issue usually occurs when the lithium-ion batteries capacity is permanently lost. This usually occurs with repetitive charging.
Scientists at the Indian Institute of Technology Gandhinagar (IITGN) have created an adaptive charging method for lithium-ion batteries that could improve the efficiency of Electric Vehicle (EV) charging while limiting a key degradation issue known as lithium plating. Appearing in the Journal of Energy Storage, the research presents a self-regulating charging system that continuously adjusts to protect batteries from internal damage while optimising charging speed and efficiency under different temperature and health conditions.
Lithium plating takes place when lithium-ion batteries are charged too rapidly, exposed to low temperatures, or kept at high charge levels. In such conditions, lithium fails to properly embed into the graphite anode and instead forms a metallic coating on its surface. This leads to permanent capacity loss and can create sharp, needle-like structures that may damage internal components, potentially causing short circuits or thermal fires.
Mr Shiv Shankar Sinha, the study’s lead and corresponding author who is a doctoral researcher at IITGN’s Department of Electrical Engineering and a member of the Smart Power Electronics Laboratory. He indicated that fast charging is one of the most important expectations users have from electric vehicles today, but aggressive charging can accelerate battery degradation.
“Conventional charging systems often use fixed charging patterns that do not adapt to changing battery conditions. But batteries are not static systems. Their behaviour changes with temperature, operating history, and age,” explained Professor Pallavi Bharadwaj, Assistant Professor at the Department of Electrical Engineering and the Principal Investigator of Smart Power Electronics Laboratory.
To tackle this issue, the researchers created a refined five-stage adaptive Multi-Step Constant Current (MSCC) charging method. Unlike traditional fixed charging profiles that assume a battery is always brand new and operating at an ideal room temperature, this new approach dynamically recalibrates its step limits at the start of each charging cycle. It does so by taking into account the battery’s real-time State of Age (SOA) and surrounding Battery Ambient Temperature (BAT). In effect, the system works like an intelligent controller that continuously supervises the process, detecting the precise voltage point at which lithium plating is likely to begin under varying environmental or ageing conditions, and immediately reduces the current to a safer level to avoid plating and potential cell damage.
To detect the early signs of lithium plating, the team introduced a monitoring technique based on shifts in internal battery impedance. They employed Rest-Interrupted Constant Current (RICC) testing, where charging is briefly paused at set intervals to capture subtle impedance changes linked to the onset of plating. In addition, they applied the Taguchi optimisation method, a well-known statistical design technique, to fine-tune the ideal current levels for each step of the charging profile.
The effectiveness of the method was experimentally confirmed using commercial Panasonic NCR18650B nickel-cobalt-aluminium (NCA) lithium-ion cells. Testing was carried out across a broad range of conditions prone to lithium plating, including temperatures from -5°C to 25°C, and battery health states ranging from new cells to those degraded by up to 15%.
The study reports that the new charging approach increased charge capacity utilisation by 10.65% and improved charging efficiency by 0.55% when compared with a standard plating-aware method. The researchers further found that it consistently minimised lithium plating across a wide range of temperatures and different levels of battery ageing. Mr Sinha indicated that the strategy shifts part of the safety burden from hardware-intensive protection systems to an intelligent software framework, which can be integrated within the battery management system.
The researchers also highlight that the real-world relevance of this work aligns closely with major developments in public policy and transport infrastructure, in India and internationally. As electric mobility expands through programmes such as FAME, the National Programme on Advanced Chemistry Cell (ACC) Battery Storage, and growing investments in public charging networks, there will be an increasing need for battery systems capable of performing reliably under varied climate conditions and long-term operational demands.
