Lithium titanium oxide or commonly known as LTO-anode based lithium ion batteries are popular choice for electric vehicles (EV’s) and hybrid electric vehicles (HEV’s) thanks to their extended cycle life and fast charging capabilities. It also outperforms graphite as negative electrode in terms of safety and calendaric storage. This ageing study consists of extensive cycle life tests of 56 commercially available first generation EIG 5Ah pouch cells at 27 different test conditions including three DoD levels (20%, 50%, 90%), four temperatures (-15°C, 10°C, 25°C, 45°C), several C-rates or nominal capacity rates (0.5C to 5C) and with mid-State of Charge (SoC) (50%). The studied cell type has Lithium Nickel Cobalt Aluminium Oxide (NCA) as cathode material with nominal voltage of 2.2V. The capacity evolution of all the cells are compared and analyzed in this paper explaining the impact of depth-of-discharge (DoD), temperature and C-rate on cycle ageing. Results show that indeed, LTO cells have longer cycle life and the capacity retention has only reached the end-of-life (EoL) threshold (State of health/SoH < 80% of nominal capacity) at elevated temperature (45°C). At room temperature, with 90% DoD cycling, the cells have survived more than 4500 cycles so far and the tests are ongoing. Interestingly, most of the cells had negative capacity fade at investigated temperatures. These type of LTO cells are also capable of fast charging and have performed well under stressed discharge conditions.
Original languageEnglish
Title of host publicationEVS 31 & EVTeC 2018
PublisherEVS31
Pages1-6
Number of pages6
Publication statusPublished - 2018
EventEVS31 - Kobe, Japan
Duration: 30 Sep 20184 Oct 2018

Conference

ConferenceEVS31
CountryJapan
CityKobe
Period30/09/184/10/18

    Research areas

  • LTO, capacity increase, NCA, cycling ageing, capacity evolution, degredation factors

ID: 41503150