The Taipei company’s ‘Immersio’ modular battery pack technology for vehicles directly submerges lithium-ion battery cells in non-conductive cooling fluid.
“Immersion cooling in EVs is now widely considered to be the most effective method of cooling due to its 100% cell-to-coolant contact and improved cell temperature uniformity,” according to Xing. “Castrol’s recently launched ‘On e-thermal fluid’ is circulated through Xing Mobility’s system at a dynamic flow rate to provide battery thermal management that enables improved efficiency and is especially designed to meet the challenging specifications, conditions and safety demanded by these applications.”
According to Castrol, air cooled batteries are a popular choice, especially amongst early generation electric vehicles but, while relatively simple and cheap, can perform poorly in extreme conditions and climates. Indirectly fluid-cooled battery systems used fluid with higher heat conductivity than air, but are still limited during operations such as sustained ultra-fast charging and hard driving. “Next-generation battery electric vehicles are moving to direct cooling to enable ultra-fast charging at sustained rates and improved battery system and vehicle performance.”
Of its thermal management e-fluid Castrol claims: lower viscosity compared with conventional dielectric fluids such as transformer fluids, strong electrical insulation, high flash point and oxidation resistance.
Xing has three example systems for earth movers using Li-NMC cells:
- Small excavator (60S) 32 kWh
168 – 249V
35 – 46kW continuous discharge
17…25 kW continuous charge
3,000 cycle life - Tractor (96S) 50kWh
249 – 398V
52 – 84kW continuous discharge
25 – 40kW continuous charge
3,000 cycle life - LHD loader (180S) 95kWh
504 – 747V
106 – 157kW continuous discharge
50 – 75kW continuous charge
3,000 cycle life
All figures depend on operating environment
Websites are:
Castrol e-Fluids