Published in THE ENGINEER on the 15th February 2024
Authors: Christoph Birkl, CEO and co-founder and Damien Frost, CTO and co-founder of Brill Power
February 2024, Oxford, UK – As the journey towards net zero gathers pace, we’re seeing a global focus on renewable sources and battery technology. By 2033, the value of the global sodium-ion battery market is expected to reach $4.2 billion, positioning it as a favoured and more sustainable alternative to traditional battery technology.
Unlike traditional batteries, sodium-ion chemistry helps reduce the reliance on expensive and geographically-concentrated materials such as lithium or cobalt, while also offering the opportunity to reduce costs and waste – and optimise energy usage.
Yet EVs and battery energy storage systems are currently reliant on conventional battery chemistries such as lithium-ion. As a result, more focus is being placed on delivering a cost-effective and truly sustainable solution as the automotive and stationary storage industries look beyond existing battery chemistries and technologies.
Charging forward with sodium-ion batteries
Abundant in materials and less toxic than traditional chemistries, sodium-ion can provide a step change in costs for sustainable batteries. Complementary benefits of sodium-ion chemistry include the ability to transport battery systems with the battery terminals directly connected and the voltage held at zero, mitigating safety risks and reducing cost. Sodium-ion electrolytes are also less likely to ignite, improving safety during operation.
Yet these benefits also bring challenges in operating Sodium-ion batteries, notably the ability for battery management systems to control and operate battery cells and modules at very low voltage.
Though BMS technology specific to sodium ion chemistry is still in the early stages of development, it will provide the battery industry with the opportunity to reduce the total cost of ownership for customers, while enabling developers to create the safest, most reliable battery systems.
BMS technology can help to pave the way to a greener future, by making us less reliant on materials such as cobalt which are geographically concentrated and come with environmental concerns.
Going beyond traditional BMS technology
The role of traditional BMS technology is to ensure batteries can be operated safely and provide oversight of battery health and performance. However, standard battery systems are limited by the weakest cell’s performance. Different cells degrade at different rates, resulting in many of them being underutilised, and the system’s overall lifespan decreasing.
The need to increase battery life and reliability is very real. To answer this challenge, the team at Brill Power has developed a chemistry-agnostic, hardware solution, called BrillCore, to replace traditional BMS technology. It addresses the pressing issues of battery lifespan, predictability and flexibility, while also reducing waste, and increasing sustainability benefits.
Our partnership with Faradion, a world leader in sodium-ion cell technology, and Nation Energie – in which we supported the introduction of Faradion’s sodium-ion batteries for commercial and industrial stationary storage systems in Australia – highlights the advantages of BrillCore’s patented active loading technology and battery expertise.
What sets our BMS apart from conventional management systems is the active loading technology that enables batteries to last up to 60% longer, to charge faster, and to be optimised for better performance as they age. It does this by actively loading cells or groups of cells with current in proportion to their state of health, in real time. Stronger cells are exposed to higher current and weaker cells lower current, meaning unlike conventional battery systems the performance of each system is no longer defined by the weakest performing cell.
BMS technology relies on modelling to estimate the remaining energy in a battery, based on voltage, current and temperature measurements. These models are crucial because different types of cells operate uniquely, and the quality of the battery model has a significant impact on the accuracy of state of charge and state of health estimates.
To unlock as much of the voltage window of sodium-ion as possible, a DC-to-DC converter is needed. BrillCore is unique in this regard as it integrates power electronics into the BMS to improve its performance. Consequently, we can tap into up to 46% more energy from aged batteries as well as deliver faster charging rates and improved safety.
Working with Faradion, we were able to make their sodium-ion technology a reality in the battery energy storage market, with total throughput on their systems having already exceeded 19MWh, and other benefits around wider operating temperature range, high-energy density, and improved battery safety also being realised.
Driving sustainability with agnostic systems
With further research, the battery industry can continue to find ways to maximise sustainable battery technology. We predict that over the next few years, more sophisticated BMS topologies focused on extracting the maximum performance from different cell types and chemistries will gradually replace traditionally passive systems. Combined with ongoing improvements in battery modelling, this will increase and help to optimise the performance of any type of battery.
The challenge facing the industry is to provide enough voltage and current for diverse systems, regardless of their power sources, to promote sustainability and provide better battery life value.