These next-generation batteries can store more energy, giving electric cars a longer driving range at a lower cost. The study, published in Energy and Environmental Science, shows that simply exposing battery materials to air during manufacturing can create hidden damage that speeds up battery wear over time. The researchers focused on materials used to make high-nickel cathodes, one of the key parts of a lithium-ion battery. By adding a little more lithium during the battery manufacturing process, they were able to prevent the defective surface from forming. Instead, paying closer attention to how battery materials are stored before production and carefully adjusting the amount of lithium used during manufacturing could significantly improve battery durability.