Lithium-Ion Overview

Lithium-ion batteries are used in consumer electronics like cell phones and laptops, as well as electric vehicles. The Stationary battery packs that power your home or business, (known as Stationary Energy Storage Systems) are these days mostly made up of lithium-ion batteries rather than Lead-Acid batteries. We will examine the good reasons for this our article section on comparing Lead Acid with Lithium-ion.

These batteries are easier to re-charge, deliver more of their capacity as usable energy and are generally safer than their lead-acid equivalents.

One of the reasons they are safer and last longer than Lead-Acid batteries is because they are more tolerant of what battery engineers call abuse. Abuse in the battery world means overcharging a battery or drawing current from it very fast or running it till it’s completely flat. 

 During overcharging the electrode materials decompose. This problem was easily noticed in batteries using lithium cobalt oxide (LiCoO2) as the positive electrodes. The electrode literally crumbles away inside the battery. This has been solved by using Lithium-ion phosphate (LiFePO4) which experiences less stress under those conditions than Lead-acid or other kinds of lithium-ion batteries. Lithium Iron phosphate cells (LiFePO4) now dominate in electric vehicles and in stationary energy storage systems for home and businesses. Lithium-ion battery manufacturers also supply a Battery Management System (BMS) with their batteries. This system is matched to the battery to protect batteries from harm and to optimise their performance during use too. 

Pic of Structure of a lithium-Ion battery from closedloop.fi

LiFePO4 batteries have an expected service life when used in off-grid systems where they are used every day of 13 to 15 years. If they are used in a backup power role where they are not used every day (called occasional cycling) but only when other sources of power are not available, they can last as much as 20 years. The end of life (EoL) is defined by the cells containing 70% of their beginning of life (BoL) capacity. The capacity deterioration over time is however linear (the deterioration does not become substantially more rapid with extended use), and the cells could, therefore, be used for much longer periods if a lower EoL capacity is acceptable to you.

Lithium-ion batteries are made using different chemical compositions. This overview of the different types of Lithium-ion batteries is our summary of an article which gives greater detail. It can be found at https://batteryuniversity.com/learn/article/types_of_lithium_ion

Lithium Iron Phosphate(LiFePO4) — LFP

Phosphate as a cathode material was discovered in 1996. Li-phosphate chemistry offers low internal resistance in the battery facilitating the easy flow of electrical current. These batteries are not subject to the overheating that has been associated with certain battery chemistries and are safe for powering homes and businesses even if abused. Abuse in the battery world means overcharging a battery and drawing current from it very fast or running it till it’s completely flat. Lithium-ion phosphate experience less stress under those conditions than other lithium-ion batteries.

Lithium Cobalt Oxide(LiCoO2) — LCO

This was the original combination used for mobile phones, laptops and digital cameras. The cathode is made of cobalt oxide and the anode of graphite carbon. These batteries, however, don’t last as long as more modern batteries and tended to overheat. The Li-cobalt has lost favour in consumer electronics to Li-manganese, NMC and NCA because of the high cost of cobalt and improved performance of other chemical combinations.

Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2) — NMC

These batteries have a cathode made of a combination of nickel-manganese-cobalt (NMC).

Reducing cobalt content saves money because of the high cost of cobalt. Nickel-based systems store more energy in a smaller space, cost less and are able to deliver more cycles before being used up, than the LCO batteries. 

Lithium Manganese Oxide (LiMn2O4) — LMO

Li-ion with lithium manganese oxide making up the cathode first appeared in 1996. These batteries are shorter-lived than other Lithium-ion alternatives.  They do have comparatively low internal resistance and are not prone to overheating making them a safe option in consumer electronics. They do allow very fast charging and high current discharge.

Lithium Nickel Cobalt Aluminum Oxide (LiNiCoAlO2) — NCA

Lithium nickel cobalt aluminum oxide battery, or NCA, has been around since 1999 but is not widely used. It delivers similar performance to the NMC batteries but is expensive and is not as stable and safe as other Lithium options.

Lithium Titanate (Li2TiO3) — LTO

Batteries with lithium titanate anodes have been known since the 1980s. Li-titanate replaces the graphite in the anode of a typical lithium-ion battery and the material forms into a spinel structure. The cathode can be lithium manganese oxide or NMC. Li-titanate excels in safety, low-temperature performance and life span. Efforts are being made to improve the specific energy and lower cost.

 The impact of Lithium-ion on everyone’s battery choices

Lithium-ion batteries have been consistently falling in average price in the USA and that trend is expected to continue as the technology matures.

Lithium Iron Phosphate (LiFePo4) batteries are being delivered in ever increasing volume as price becomes competitive with lead-acid and availability around the globe keeps increasing. The estimated money spent on batteries with this chemistry in 2018 was 6.14 billion US dollars. If you’re buying LiFePo4 you’re in good company and investing in a technology with a great future. The growth in the amount of electrical power the battery market produced is shown in the graphic below, the growth is measured megawatt-hours and in monetary terms in billions of US dollars. 

Lithium-Iron Phosphate batteries conclusion:

They are the battery of choice in powering homes and businesses and the battery of choice for REVOV (stationary energy storage systems). These batteries are widely used in electric vehicles and consumer electronics and so have a proven safety record. 2nd LiFe versions of these batteries are comparable in price to Lead-Acid packs that deliver the same output. They last usually three times as long as Lead-Acid batteries, have fewer safety risks and require negligible maintenance. They tolerate abuse and big variations in temperature and are significantly cheaper to keep charged up.