Lithium Energy Storage For Off Grid Solar Systems


Lithium ion batteries were first introduced to the market back in 1991. These early offerings utilized the metallic form of lithium which possessed a very high energy density. Unfortunately along with the high energy density came a higher propensity for thermal runaway. Thermal runaway in lithium ion battery is a rapid, exothermic reaction that causes the cell to self destruct, The hotter the cell gets the more reactive the remaining lithium in the cell becomes. The heat from a single cell in thermal runaway can propagate to neighboring cells in the battery back resulting in the release of noxious gasses, fire and even the possibility of explosion.

Following the catatrophic failure of several of these earlier metallic lithium based battery designs, the industry shifted to a non mettalic lithium ion alternative. This new design offered lower energy density than metallic lithium but provided better thermal stability. Today there are several different types of lithium ion battery chemistries available on the market.

1. Lithium Colbalt LiCoO2

2. Lithium Manganese Oxide LiMn2O4

3. Lithium Iron Phosphate LiFeO2

4. Lithium Nickel Manganese Cobalt Oxide LiNiMnCoO2

5. Lithium Nickel Cobalt Aluminum Oxide LiNiCoAlO2

6. Lithium Titanate Li4Ti5O12

When it comes to cost, specific energy, thermal stabilty, lifespan, power density and safety, each battery chemistry offers advantages and disadvantages. For example, Lithium Colbalt LiCoO2 and Lithium Nickel Cobalt Aluminum Oxide LiNiCoAlO2 offer increased specific energy.

While residential energy storage systems do come equipped with both active and passive cooling systems as well as a built-in BMS (Battery Management System), it is this author's opinion that it is best to start with a battery chemistry that is inherently safer and less dependent on these external safety systems should those safety systems fail.

LG off grid storage battery systems are now available for both residential and commercial applications.. LG off grid battery systems offer a safer chemistry than the batteries that are typically used in electric vehicles as well as a longer cycle life, better power density, and offer a slower rate of capacity loss and a much better value than potentially volatile chemistries that contain toxic materials and comparatively short lived lead acid storage technology.