Researchers at Indian Institute of Technology, Madras, have developed a control framework for electric vehicle (EV) traction systems that can extend driving range by improving the efficiency of regenerative braking, without requiring hardware changes.

Regenerative braking allows EVs to recover energy during deceleration, but it becomes ineffective below a certain speed. In most systems, this low-speed cut-off is fixed using empirical methods that do not adapt to operating conditions, leading to energy loss.

The IIT-Madras team addresses this by introducing an analytical method to determine the speed below which regenerative braking should be disabled. It is derived from first principles and computed offline, avoiding additional computational load during real-time vehicle operation.

In addition, the researchers developed a model-based algorithm that dynamically adjusts the motor’s magnetic flux depending on speed and torque conditions. This replaces conventional fixed-flux operation, reducing power losses and extending the effective range over which regenerative braking can function.

The framework has been tested using both international and Indian driving cycles, including the modified Indian drive cycle (MIDC). Results show a reduction in traction system losses of up to 13 per cent under MIDC conditions and about 7 per cent under the US EPA highway cycle.

The paper, published in the journal IEEE Transactions on Transportation Electrification, was co-authored by research scholar MK Deepa, Prof Srikanthan Sridharan and Prof CS Shankar Ram.

The team plans to test the framework on full-scale EVs to assess system-level effects, including battery performance and thermal behaviour, and explore its integration with battery state-of-charge management.

Stable aluminium-ion battery

Researchers have developed a composite electrode material that improves the durability of aluminium-ion batteries, potentially making them cheaper, safer and longer-lasting.

Aluminium batteries are being explored as an alternative to lithium-ion systems because aluminium is abundant, inexpensive and can store more charge per atom. However, poor durability is a major hindrance: The electrode material tends to crack or dissolve into the electrolyte during repeated charging and discharging cycles, leading to rapid loss of performance.

A commonly used cathode material, vanadium oxide, can store high energy and allows aluminium ions to move through its layered structure. But in water-based aluminium batteries, it dissolves into the electrolyte, causing the battery to lose capacity quickly.

To address this, a team led by Kavita Pandey at the Centre for Nano and Soft Matter Sciences, working with researchers from the Shiv Nadar Institution of Eminence, combined vanadium oxide with MXene, a highly conductive, ultra-thin material.

In this composite, MXene forms a conductive network that stabilises the vanadium oxide and provides smooth pathways for ion movement. “This significantly reduces the dissolution of vanadium into the electrolyte — from 28.3 ppm in pure vanadium oxide to 5.4 ppm in the composite,” says a press release.

As a result, battery performance improves markedly. The composite retains over 73 per cent of its original capacity after 100 charge cycles and about 59 per cent even after 500 cycles, substantially better than conventional designs.

Further analysis showed that the MXene framework helps preserve the electrode’s structure during operation, preventing the cracks and damage that typically degrade aluminium-ion batteries.

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Published on April 20, 2026