Lithium Iron Phosphate Battery

The lithium iron phosphate battery (LiFePO₄ battery) or LFP battery (lithium Ferro phosphate), is a type of rechargeable battery, specifically a lithium-ion battery, using LiFePO₄ as the cathode material, and a graphitic carbon electrode with a metallic backing as the anode. The specific capacity of LiFePO₄ is higher than that of the related lithium cobalt oxide (LiCoO₂) chemistry, but its density is less due to its lower operating voltage. The main drawback of LiFePO₄ is its low electrical conductivity. Therefore, all the LiFePO₄ cathodes under consideration are actually LiFePO₄/C. Because of low cost, low toxicity, well-defined performance, long-term stability, etc. LiFePO₄ is finding a number of roles in vehicle use, utility scale stationary applications, and backup power.

Lithium Iron Phosphate LiFePO4, each Cells 700 Ah Amp Hours 3.25 Volts. Two cells are wired in parallel to create a single 3.25V 1400Ah cell, with a capacity of 4,550 Watt hours or 4.55 kWh. Note the multi-layer copper bus bar designed to carry more electrons on the surface of multiple plates rather than using a single solid connector between cells. Higher discharge rates needed for acceleration, lower weight and longer life makes this battery type ideal for bicycles and electric cars. 12V LiFePO₄ batteries are also getting popularity as a second (house) battery for a caravan, motor-home or boat.

LiFePO₄-powered solar lamps are visibly brighter than ubiquitous outdoor solar lights, and performance overall is considered more reliable. Many home EV conversions use the large format versions as the car's traction pack. With the efficient power-to-weight ratios, high safety features and the chemistry's resistance to thermal runaway, there are few barriers for use by amateur home "makers". Motorhomes are often converted to lithium iron phosphate because of the high draw. Some electronic cigarettes use these types of batteries. Other applications include flashlights, radio-controlled models, portable motor-driven equipment, industrial sensor systems and emergency lighting. 

Lithium–Air Battery

The lithium–air battery (Li–air) is a metal–air electrochemical cell or battery chemistry the uses oxidation of lithium at the anode and reduction of oxygen at the cathode to induce a current flow. Pairing lithium and ambient oxygen can theoretically lead to electrochemical cells with the highest possible specific energy. Indeed, the theoretical specific energy of a non-aqueous Li–air battery, in the charged state with Li₂O₂ product and excluding the oxygen masks, is ~40.1 MJ/kg. This is comparable to the theoretical specific energy of gasoline, ~46.8 MJ/kg. In practice, Li–air batteries with a specific energy of ~6.12 MJ/kg at the cell level have been demonstrated. This is about 5 times greater than that of a commercial lithium-ion battery, and is sufficient to run a 2,000 kg EV for ~500 km (310 miles) on one charge using 60 kg of batteries.

 However, the practical power and life-cycle of Li–air batteries need significant improvements before they can find a market niche. Significant electrolyte advances are needed to develop a commercial implementation. Four approaches are active: aprotic, aqueous, solid state and mixed aqueous–aprotic. Metal–air batteries, specifically zinc–air, have received attention due to potentially high energy densities. The theoretical specific energy densities for metal–air batteries are higher than for ion-based methods. Lithium–air batteries can theoretically achieve 3840 mA·h/g.

A major market driver for batteries is the automotive sector. The energy density of gasoline is approximately 13 Kw h/kg, which corresponds to 1.7 kW·h/kg of energy provided to the wheels after losses. Theoretically, lithium–air can achieve 12 kW·h/kg (43.2 MJ/kg) excluding the oxygen mass. Accounting for the weight of the full battery pack (casing, air channels, lithium substrate), while lithium alone is very light, the energy density is considerably lower. A Li–air battery potentially had 5–15 times the specific energy of a Li-ion battery.

Magnesium Battery

Magnesium batteries are batteries that utilize magnesium cations as the active charge transporting agent in solution and as the elemental anode of an electrochemical cell. Both non-rechargeable primary cell and rechargeable secondary cell chemistries have been investigated. Magnesium primary cell batteries have been commercialised and have found use as reserve and general use batteries. Primary magnesium cells have been developed since the early 20th century. A number of chemistries for reserve battery types have been researched, with cathode materials including silver chloride, copper(I) chloride, palladium(II) chloride, copper(I) iodide, copper(I) thiocyanate, manganese dioxide and air (oxygen). For example, a water activated silver chloride/magnesium reserve battery became commercially available by 1943.

 Magnesium secondary cell batteries are an active topic of research, specifically as a possible replacement or improvement over lithium-ion–based battery chemistries in certain applications. A significant advantage of magnesium cells is their use of a solid magnesium anode, allowing a higher energy density cell design than that made with lithium, which in many instances requires an intercalated lithium anode. Insertion type anodes ('magnesium ion') have also been researched, primarily as heavy main group metal thin films or as Zintl phases, for instance Mg₂Sn.

A magnesium–air fuel cell has theoretical operating voltages of 3.1 V and energy densities of 6.8 kwh/kg. General Electric produced a magnesium air fuel cell operating in neutral NaCl solution as early as the 1960s. The magnesium air battery is a primary cell, but has the potential to be 'refuelable' by replacement of the anode and electrolyte. Magnesium air batteries have been commercialised and find use as land based backup systems as well as undersea power sources, using seawater as the electrolyte.