A Wide Range of Testing Results on an Excellent Lithium-Ion Cell Chemistry to be used as Benchmarks for New Battery Technologies

Abstract

We present a wide range of testing results on an excellent moderate-energy-density lithium-ion pouch cell chemistry to serve as benchmarks for academics and companies developing advanced lithium-ion and other "beyond lithium-ion" cell chemistries to (hopefully) exceed. These results are far superior to those that have been used by researchers modelling cell failure mechanisms and as such, these results are more representative of modern Li-ion cells and should be adopted by modellers. Up to three years of testing has been completed for some of the tests. Tests include long-term charge-discharge cycling at 20, 40 and 55°C, long-term storage at 20, 40 and 55°C, and high precision coulometry at 40°C. Several different electrolytes are considered in this LiNi 0.5 Mn 0.3 Co 0.2 O 2 /graphite chemistry, including those that can promote fast charging. The reasons for cell performance degradation and impedance growth are examined using several methods. We conclude that cells of this type should be able to power an electric vehicle for over 1.6 million kilometers (1 million miles) and last at least two decades in grid energy storage. The authors acknowledge that other cell format-dependent loss, if any, (e.g. cylindrical vs. pouch) may not be captured in these experiments.

Degradation Cost Analysis of Li-Ion Batteries in the Capacity Market with Different Degradation Models

“…First, degradation models can be outdated because all degradation models need to be fitted based on the experimental battery data which has changed hugely over the years due to the advancement in battery materials. For example, the capacity fade in a more recent work for the NMC battery cell can be only around 7% after 4500 cycles and less than 1% after 450 day [74]. Second, a battery asset owner can utilise the battery to provide many other different ancillary services which is not considered in this study.…”

Challenges and Strategies for Fast Charge of Li‐Ion Batteries

“…Taking structural instability of the spherical secondary structure and large surface area of the nanosized primary particles into consideration, single‐crystal materials are in principle beneficial to stabilizing the performance of the layered cathode. For example, Harlow et al demonstrated that in a wide temperature range (20∼55 °C), the Li‐ion cells employing single‐crystal NMC532 provide far longer lifetimes when compared with cells using spherical aggregates. The increased lifetime is attributed to two properties of the single‐crystal materials: (1) intrinsically better stability of the single‐crystal primary structure compared to the spherical secondary structure, and (2) significantly smaller specific surface area of the large single‐crystals compared to the nanosized primary particles.…”

A Circular Economy of Electrochemical Energy Storage Systems: Critical Review of SOH/RUL Estimation Methods for Second-Life Batteries

“…However, it is likely that they will be changed before they reach the 80% threshold not because they do not work properly but because there are other battery technologies and chemistries that will get better in the near future. For example, a recent study by Professor Jeff Dahn's group at Dalhousie University and Tesla Canada presented a LIB testing benchmark where they included a battery with a lifetime of around 4600 cycles (1.600,000 km driving range), at extreme discharging conditions (i.e., bringing the battery to a full discharge in each cycle), which could also be employed in energy storage for 20 years after reaching its EV end of life [20]. Still, even if novel batteries will get more cost-effective and safer, the battery manufacturing processes remain energyintensive [21].…”