The development of advanced autonomous mobile robots (AMRs) is essential for achieving the flexible work environment necessary for smart manufacturing. Complex perception, locomotion and navigation systems comprised of many sensors and powerful processors allow AMRs to continuously monitor their surroundings and internal systems. AMRs that can move freely around an industrial facility are increasingly required for 24/7 industrial processes. The energy requirements of AMRs can include the need for high power for tasks such as lifting and transporting as well as low power for the various onboard sensors. Total operating time between charges is dependent on factors such as distance travelled, payload power consumption, payload/cargo mass and AMR attachments such as tilt trays or robotic arms.
When designing a battery, one must be aware of the application and the trade-offs in terms of cost, electrochemical performance, and environmental impact. Desirable qualities for AMR batteries include high level of safety, high specific energy and specific power, high energy and power densities, high Coulombic efficiency, fast charge and slow discharge rates, long lifetime, low cost, and minimal environmental impacts. Safety is of primary concern for AMRs, especially in the early development of the technology, as destruction of infrastructure, accident and injury claims, and negative publicity could be a huge setback.
A summary of batteries used in commercial AMRs revealed that Li-ion batteries are the most common type of power source. Specifically, Li-ion batteries containing a LiFePO4 cathode, and a graphite anode are the most ubiquitous. Individual LiFePO4/graphite cells are connected in a combined series/parallel arrangement in battery packs to achieve the desired voltage and capacity values.
