The number of EVs being sold annually is generally increasing. According to a study published by Lai et al. in 2022, 18 million EVs will be sold between 2025 and 2030, averaging 3.6 million per year. In an effort to make both the production process and the cars themselves more efficient, giga-casting has emerged as a popular topic. It is a technology that has been proven to reduce the overall weight of the EVs, increasing their range while, contrary to popular belief, not compromising their repairability. Another relevant matter worth analyzing is the lifecycle of these millions of vehicles, particularly their lithium-ion batteries. When they’re still at a relatively high capacity of 70 to 80 percent, they have to be disposed of due to safety reasons (Chen et al., 2023), and the current mainstream methods simply aren’t cutting it. When they aren’t incorrectly disposed of, the methods of recycling that do exist, like hydrometallurgy, often use harmful chemicals in order to extract the lithium (Stegemann & Gutsch, 2025). The cathode-to-cathode version of direct recycling seems to address most of the recycling issues, and while it isn’t used at a large scale yet, I believe it is the best option we have for the estimated 12.95 million tons of spent lithium batteries that will accumulate by 2030 (Lai et al., 2022). For those looking for a partial alternative to lithium, the new mass-produced battery by Changan incorporates sodium-ion batteries. My goal here is to provide a basis for a deeper dive into these fascinating concepts.Giga casting is not the compromise everyone thinks it isThe general idea is this, instead of casting a bunch of smaller pieces and welding them all together, giga-casting creates a single. large part, saving weight and directly increasing range. Tesla and the Model Y have been using this since 2019, replacing the 70 parts comprising the rear floor and the accompanying 1600 welds (Li et al., 2025). The technology used for these giga-casts is vacuum high pressure die casting, an optimized version of regular high-pressure die casting which eliminates many of the defects that occur with making these large parts (Yang et al., 2023). These presses reach around 9000 tons of clamping force (Li et al., 2025). Where giga-casts draw most of their criticism is from their innate characteristic of being a singular part. When a regular non-giga-cast part gets damaged, repairs are made by cutting the welds around the damaged section and replacing it, and well, since giga-casts don’t have any welds, the entire part supposedly needs to be replaced, increasing the overall cost. Research conducted by Kreutner et al. in 2025 resulted in a few findings that dispute and minimize this. The first being that the collisions in which giga-casts are damaged are often so severe that the car is set to be totaled anyway. This makes sense, you don’t damage structural elements like the rear floor present in the mentioned Model Y in a fender bender. Another finding corroborated by Wang et al. is that giga-cast parts can be repaired in a similar manner to the welds by cutting out the damaged section, with both Tesla and GM offering visual guides for technicians to use.A New form of Battery Recycling: Cathode to CathodeYou’ve probably heard of refurbished iPhones or computers, which take a worn device and repair it. Cathode to cathode direct recycling is a process that does a similar thing. After breaking down the battery and retrieving the lithium, a lithium based solution is then applied to it restoring it to full capacity (Chen et al., 2023). During this, other rare earth metals are also recovered from the battery (Yang et al., 2023). The advantages to this revolve around the fact that the lithium can be put back into the supply chain to create other batteries which reduces the amount of mining that needs to occur.Sodium Batteries: A Non-Lithium Alternative?While lithium ion batteries are great for their high density, sodium is around 1000x more abundant, making it more accessible as a battery material (Cai et al., 2024). Traditionally, due to their higher weight and therefore lower density, they were considered for more casual applications, but Changan’s new battery made in collaboration with CATL might’ve changed that. The battery being used in their EVs is a dual chemistry battery, benefiting from a pairing of both the high energy density of the lithium ion batteries, with the stability and reliable discharge power of the sodium ion batteries (Awan, 2026). While not quite as exciting as solid-state batteries, the development of sodium-ion batteries offers a safer variety in the EV battery market.SourcesLai, Xin, Quanwei Chen, Xiaopeng Tang, et al. “Critical Review of Life Cycle Assessment of Lithium-Ion Batteries for Electric Vehicles: A Lifespan Perspective.” eTransportation 12 (May 2022): 100169. https://doi.org/10.1016/j.etran.2022.100169.Li, Zhongyao, Yisheng Miao, Shihao Wang, Qinghuai Hou, Ye Tian, and Junsheng Wang. “Research Progress on Giga-Cast Technology of Aluminum Alloys.” AFC, 2025. https://afc.foundrynations.com/uploads/pdf/2025afc/07-1135.pdf.Yang, Jian, Bo Liu, Dongwei Shu, Qin Yang, and Tiegang Hu. “Vehicle Giga-Casting Al Alloys Technologies, Applications, and Beyond.” Journal of Alloys and Compounds 1013 (January 2025): 178552. https://doi.org/10.1016/j.jallcom.2025.178552.Stegemann, Luca, and Moritz Gutsch. Environmental Impacts of Pyro- and Hydrometallurgical Recycling for Lithium-Ion Batteries - A Review. 2025.Chen, Quanwei, Xin Lai, Yukun Hou, et al. “Investigating the Environmental Impacts of Different Direct Material Recycling and Battery Remanufacturing Technologies on Two Types of Retired Lithium-Ion Batteries from Electric Vehicles in China.” Separation and Purification Technology 308 (March 2023): 122966. https://doi.org/10.1016/j.seppur.2022.122966.Cai, Xiaosheng, Yingying Yue, Zheng Yi, Junfei Liu, Yangping Sheng, and Yuhao Lu. “Challenges and Industrial Perspectives on the Development of Sodium Ion Batteries.” Nano Energy 129 (October 2024): 110052. https://doi.org/10.1016/j.nanoen.2024.110052.Awan, Z. (2026, February 12). Changan and CATL launch world’s first mass-production sodium-ion EV. 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