THE BATTERIES BEHIND THE WELLS
Presently, there are great number of battery manufactures out there who produces millions of batteries every month, but in a situation where most electric cars are fitted with 8,000 batteries and above, it make a lot of sense to start questioning manufactures ability for meet up with growing demands which has recently been on the increase. We are going to take a quick look at these batteries and the advantages they off as well as the possibility we are not going to run out of batteries or materials for making them one day.
Technology and cost challenges Current battery performance of lithium-ion batteries is not sufficient to be widely used for HEVs, PHEVs, and EVs. In addition to necessary increases in energy and power density (performance), other improvements are needed in durability, safety, and cost.
Durability: Batteries in PHEVs and EVs are required to have reliable durability for deep cycles to keep longer life (The Institute of Applied Energy, 2008). Vehicle makers are aiming to develop lithium-ion batteries with a guaranteed five-year or 100,000 kilometer driving distance (Nishino, 2010). Deep cycles of lithium-ion battery decrease the battery capacity rapidly, but PHEVs and EVs will be charged after the battery-stored energy is almost depleted. In addition, the power of lithium-ion batteries decreases in cold weather. For use of electric vehicles in cold regions, further technology development will be necessary to overcome this problem.
Durability: Batteries in PHEVs and EVs are required to have reliable durability for deep cycles to keep longer life (The Institute of Applied Energy, 2008). Vehicle makers are aiming to develop lithium-ion batteries with a guaranteed five-year or 100,000 kilometer driving distance (Nishino, 2010). Deep cycles of lithium-ion battery decrease the battery capacity rapidly, but PHEVs and EVs will be charged after the battery-stored energy is almost depleted. In addition, the power of lithium-ion batteries decreases in cold weather. For use of electric vehicles in cold regions, further technology development will be necessary to overcome this problem.
Safety:
Lithium-ion batteries are vulnerable to short-circuiting and overcharging. Lead acid, NiCd and Ni-MH batteries perform safely even after short-circuiting and overcharging because they have low energy capacity and use inflammable electrolyte. However, when a lithium-ion battery short circuits, high electricity flows are created and the battery temperature increases to several hundred degrees within seconds, heating up neighboring cells and resulting in an entire battery combustion reaction (Jacoby, 2007). When lithium-ion batteries are unintentionally overcharged, the chemical structure of the anode and cathode are destroyed and some of the lithium ions form snowflake-shaped lithium metal deposits called “dendrites,” which can cause the battery to short circuit or, in a worse-case scenario, explode and catch fire. Impurities in the lithium metal can also contaminate the batteries and cause the formation of dendrites, potentially Lithium-ion Batteries for Hybrid and All-Electric Vehicles: the U.S. Value Chain 17 causing short circuits and explosions (Buchmann, 2007). To prevent overcharging, lithium-ion batteries must be sold as battery packs with very precise voltage control systems. In other words, cells cannot simply be installed into a given electronic application. Even though lithium batteries have a number of safety measures (see U.S. Value Chain section, page 31), further safety measures need to be developed for vehicle use. Note, these standards varies from countries to countries, thus, there is need for the implementation to a universal standard.
Lithium-ion batteries are vulnerable to short-circuiting and overcharging. Lead acid, NiCd and Ni-MH batteries perform safely even after short-circuiting and overcharging because they have low energy capacity and use inflammable electrolyte. However, when a lithium-ion battery short circuits, high electricity flows are created and the battery temperature increases to several hundred degrees within seconds, heating up neighboring cells and resulting in an entire battery combustion reaction (Jacoby, 2007). When lithium-ion batteries are unintentionally overcharged, the chemical structure of the anode and cathode are destroyed and some of the lithium ions form snowflake-shaped lithium metal deposits called “dendrites,” which can cause the battery to short circuit or, in a worse-case scenario, explode and catch fire. Impurities in the lithium metal can also contaminate the batteries and cause the formation of dendrites, potentially Lithium-ion Batteries for Hybrid and All-Electric Vehicles: the U.S. Value Chain 17 causing short circuits and explosions (Buchmann, 2007). To prevent overcharging, lithium-ion batteries must be sold as battery packs with very precise voltage control systems. In other words, cells cannot simply be installed into a given electronic application. Even though lithium batteries have a number of safety measures (see U.S. Value Chain section, page 31), further safety measures need to be developed for vehicle use. Note, these standards varies from countries to countries, thus, there is need for the implementation to a universal standard.
COST
The high cost of lithium-ion batteries for vehicle use is a critical concern. According to the most recent estimates available for batteries for vehicle use, the cost of lithium-ion is four to eight times that of lead acid and one to four times that of NiMH (Nishino, 2010). However, the cost of lithium batteries is expected to decrease significantly because the batteries will be increasingly used for many applications, such as uninterruptible power supply (UPS), forklifts, consumer electronics and backup power supplies. As the market grows and production scales up, manufacturers will be able to enjoy economies of scale. According to Deutsche Bank, the cost of lithium-ion batteries will decrease from $650/kWh in 2009 to $325/kWh by 2020 (Deutsche Bank, 2009). 
The expectation that the owner of an electric car should be able to drive it both at blisteringly hot summer temperature and at subzero winter temperatures poses substantial engineering challenges. batteries can be optimized for both high and low temperature but it is difficult to engineer them to function over a wide range of temperature without incurring performance degradation. for instance, batteries optimized for performance and endurance in cold climates would rely use electrolytes and materials that allow high temperature storage. All these and many more are to be put into consideration during production of batteries and that means a lot. Hopefully, many studies are under way, studying different conditions and proffering various solutions for better result. Tesla Motors have been doing a good job in show casing these new capacities and capabilities and has proven how much punishment a battery can take and how far they can go, at that, they have continued to pull new amazing records.
No comments:
Post a Comment