Week 6 Session 13
1)Discuss two new trends in battery system field.
sOL:-
New trends in battery system field:-
1. Lithium-Sulfur Battery
The cathode in Lithium-Ion batte
ries is composed of metal oxides from Lithium, Nickel, Manganese, and Cobalt. Among the three metal oxides, Cobalt accounts for up to 20% of the total weight of the cathode. However, it is mined from the Democratic Republic of Congo, a country that allegedly uses practices that are not socially responsible. As EV production increases around the world, the global supply chain of Cobalt has been severely hit.
Over the decade, significant progress has been made to reduce the dependence on a metal that is prone to supply shocks. Among all the technologies that are being currently studied, the Sulfur-Lithium battery is the one that is leading the race to replace Lithium-ion batteries as the source of energy storage in the future.
In the Lithium-Sulfur battery, the anode is replaced with metallic Lithium while Sulfur serves as the cathode. Discharging the battery produces Lithium-ions that move through the electrolyte. These ions interact with sulfur at the cathode end converting the sulfur into Lithium Polysulphides. This process is reversed while charging.
The primary reason why Lithium-Sulfur is one of the battery trends to expect in the future is due to its high specific energy, in the order of 450W/kg. The higher energy density of Lithium-Sulfur renders itself viable to be used in electricity storage from renewable sources.
But, Sulfur has low conductivity and requires additional carbon to help create polysulphides during the discharging phases. Repeated creation of polysulphides in the cathode end leads to an eventual decrease in the concentration of sulfur and the number of recharges.
2)Immersion cooling :-
Charging or discharging a battery pack generates heat. This heat has to be dissipated from the system. Failure to reduce the temperature of the battery can lead to adverse consequences like the battery exploding.
The most common method of cooling is air cooling. Where fresh air is allowed to move through the component reducing its temperature. This is because air has a low heat capacity and is a good conductor of heat.
Liquid or water cooling is the preferred method of cooling currently used in EVs. In this process, water/glycol solution is forced through a heat pipe that is in contact with the battery. The heat pipe is connected to a radiator which exchanges the heat with the atmosphere through convection
3)Cloud-based BMS :-
The BMS monitors the Soh (State of Health), SoC (State of Charge), voltage, current, and temperature of the battery. It plays a vital role during the charging and discharging phase of the battery by maintaining a stable temperature. During cases where the temperature of the battery increases, the BMS regulates the heat by controlling the flow of coolants in the system.
But, the BMS only has one to four sensors connected to the battery at any given time. Reducing the data points that can be collected from the battery. When the battery is stressed from more than one anomaly, this can serve as a vulnerability leading to system collapse.
Cloud-based technologies have started to permeate most aspects of everyday life through IoTs. Leveraging the computing power of cloud-based technologies allows for an exponential increase in the processing capabilities of battery management systems. Cloud-based BMS will be able to draw inferences from BMS data obtained from other vehicles in the network. Using a high-fidelity mathematical model of the battery pack, cloud-based BMS will be able to figure out places where the battery temperatures are higher than normal.