How battery management system innovation can lead to better batteries

Dr Alex Holland, Principal Technology Analyst at IDTechEx, has shared that the company forecasts the Li-ion battery market for electric vehicles to reach US$380bn by 2034.

With this huge increase in value, the safe and reliable operation of these (sometimes combustible) assets, while maximising the performance extracted from them becomes critical. The battery management system (BMS) plays a central role in the safe and reliable operation of Li-ion batteries, but is somewhat overlooked with regard to its potential for also moving battery performance forward.

Developments in battery technology often centre on material and chemistry innovations, whether in the form of silicon anodes, solid-state batteries, or new Na-ion chemistries, or on other hardware developments, such as the use of cell-to-pack battery designs or 800V platforms.

However, new materials, chemistries, and hardware often come with lengthy development and testing phases and trade-offs in performance or cost. For example, high-silicon anodes increase energy density and can improve fast charging, but come at the expense of cycle life, and in the short-term, high-silicon anode solutions are likely to come at a price premium too.

In contrast, innovations to the BMS can offer feasible routes to improving multiple performance metrics simultaneously, a feat that is notoriously difficult to achieve in Li-ion battery development. Namely, improvements to energy density, fast charge capability, safety, and cycle life can be achieved with the right BMS. Ultimately, many of these improvements will be enabled through better and more accurate state estimation (state-of-charge, state-of-power, state-of-health) and a better understanding of the internal state of the Li-ion cells, in turn allowing for more optimised use of the Li-ion battery.

For example, reducing charging times can be achieved by tracking the internal state of Li-ion cells by analysing data generated by the battery during use to look for signs of lithium plating. During periods of the charge cycle where the onset of lithium plating is determined to occur, the charging current can be reduced before being increased once the risk of lithium plating has reduced, with the aim of increasing average charging power without increasing degradation.

A number of companies, such as Eatron Technologies, WAE (via their Elysia platform), and Qnovo, amongst numerous others, are developing and deploying more advanced BMS software platforms to help enhance state estimation and optimise battery operation. Indeed, there has been a hive of activity in Europe and North America from early stage companies developing more advanced BMS technologies. Some of the advancements are starting to make their way onto the market. For example, Qnovo are looking to deploy their software in Vanderhall EVs to help improve range and charging times, while Eatron Technologies have also started to deploy their BMS software.

There are a multitude of developments happening within Li-ion battery technology. While headlines can focus on novel and next-generation battery materials, chemistries and technologies, advancements to the BMS offers a way to maximise the performance of both today’s and tomorrow’s Li-ion technology, and could therefore, play a key role in accelerating the adoption of EVs and stationary battery storage systems.