Why Choose a Li-Ion Battery Pack?

Lithium ion has the best energy density of all rechargeable battery chemistries. It’s also lightweight and has great cycle life.

Li-ion batteries can be dangerous if they are stored improperly. They can explode if the separator sheet is punctured and the electrodes come into contact with each other.

They can also degrade over time, particularly in heat. This is known as “aging.”

High Energy Density

When compared to other rechargeable battery types, Li-ion batteries have Li-ion battery pack the highest energy density. This means they can store more power in a smaller package than other battery chemistries. This allows for longer run times or shorter charging time. This feature is especially important for applications like electric VTOL aircraft that require less weight and space.

High energy density is also a key requirement for mobile power sources such as phones, laptops, and tablets. A higher energy density also helps to make battery packs smaller, which reduces weight and costs.

In addition, higher energy densities enable EVs to travel further on a charge. This is especially important as demand for zero-emission transportation grows.

Battery researchers are constantly working to improve energy density. Some of the latest improvements have resulted in cell efficiencies that approach 800 Wh/kg. While this is still below the energy density needed for commercial airplanes, it is progress in the right direction. Over vegan kebabs at CleanTechnica, we’ve heard that battery researchers expect to reach 1000 Wh/kg soon, which would be enough to power most commercial aircraft and allow for all-electric long-distance flights. That would be a game-changer.

Long Lifespan

Lithium-ion batteries have a long lifespan compared to other rechargeable battery types, such as NiMH (nickel-metal hydride). This is mainly due to the fact that lithium can be stored much more energy than other metals. A Li-ion battery pack has an energy density of 150 watt-hours per kilogram, which is significantly higher than NiMH’s 100 watt-hours per kilogram.

The longevity of a Li-ion battery is dependent on how the battery is used and maintained. Regular full discharge and charging cycles degrade the battery’s components, shortening its lifespan. Consumer-grade Li-ion batteries are designed to last for 500 charge/discharge cycles. This typically works out to two or three years of use.

To increase the lifespan of a lithium-ion battery, it is recommended to store them at around 50% SOC when not in use. In addition, avoiding high discharge rates and using original equipment manufacturer chargers is beneficial.

It is also important to note that Li-ion batteries do not have “memory” and require full discharges in order to prolong their life. However, it is important to note that each battery cycle will decrease its lifespan – a 100% Depth of Discharge (DoD) can reduce the lifespan of a lithium-ion cell by up to half compared to a lower DoD. This is because when a battery is discharged to 100% DoD, it experiences high currents and thermal stresses that can cause the electrodes to wear down more quickly than in a lower DoD condition.

Fast Charging Rate

While most lithium batteries can be charged ultra-fast, this should only be done when necessary. This is because a high charge current stresses the battery by driving the voltage to the ceiling at Stage 1 and reducing capacity during the saturation charge. The battery’s life can be extended by using a lower charging current and eliminating the saturation charge completely.

To achieve this, the battery pack must have cells that have a low internal resistance and high capacitance. This reduces power loss, gassing and metallic lithium plating during the charge process. A thicker anode design and a slower rate of charge also helps.

NREL is working to overcome this trade-off between fast charging and energy density by optimizing cathode and cell designs. Electrochemical models are used to identify the most promising pathways for improving the performance and lifetime of Li-ion batteries.

A major issue in battery technology is that the energy density of a Li-ion cell drops with cycling. This is due to various mechanisms such as solid-electrolyte interphase (SEI) formation and dissolution, thermal runaway and degradation of the active material. To reduce this energy loss, it is important to optimize the charge-discharge profile with an appropriate cycling pattern that minimizes capacity fade. This can be accomplished by monitoring the battery and using a dynamic control algorithm to adjust the charge current based on the battery status.

Lightweight

Li-ion batteries are a lightweight energy storage solution. Their high power density and cycle life Li-ion battery pack makes them ideal for many new design solutions.

Unlike Ni-Cd, Li-ion battery packs can be partially discharged without harming the cell. This allows for better utilization of the overall capacity of the pack and reduces waste. Additionally, the lithium chemistry of these batteries prefers partial discharge rather than deep discharging. This helps reduce the chances of metallic lithium plating during the life of the cell.

The first commercially available lithium ion cells were developed for portable electronic devices such as personal computers and cellular phones. Since then, significant improvements in performance and cost have been achieved due to cell chemistry/design innovations, cell engineering, and pack integration. These developments have helped to meet increasing demand for energy storage, resulting in a steep decline in battery prices.

A new class of flexible battery technologies enables the development of wearable electronics, such as smart clothing that can monitor body-related data1.

To enable these applications, lightweight and durable energy storage units are needed. To address this need, we have developed flexible lithium-sulfur full cells with high areal capacity (3 mA h cm-2), remarkable cycling stability and bending stability, and an outstanding cell energy density (288 W h kg-1 or 360 W h L-1).