Lithium solar cells have attracted great interest and attention due to their high specific energy, long cycle life, wide operating temperature range, etc. What is particularly attractive is that the average battery price per cycle is not high, and, also on a downward trend. The advantages and characteristics of lithium solar cells are introduced in more detail below.
Compared with other high-energy secondary batteries (such as Ni-Cd batteries, Ni-MH batteries, etc.), lithium-ion batteries have significant advantages in performance, mainly in the following aspects.
(1) High working voltage
Using carbonaceous lithium intercalation compounds such as graphite or petroleum coke instead of metal lithium as the negative electrode will reduce the battery voltage. However, due to their low lithium intercalation potential, the voltage loss can be minimized. At the same time, selecting a suitable lithium intercalation compound as the positive electrode of the battery and selecting an appropriate electrolyte system (determining the electrochemical window of the lithium solar cell) can make the lithium solar cell have a higher working voltage (-4V), which is much higher than that of the aqueous solution. system battery.
(2) Larger specific capacity
Although replacing metal lithium with carbonaceous materials will reduce the mass specific capacity of the material, in fact, in metal lithium secondary batteries, in order to ensure a certain cycle life of the battery, the negative metal lithium is usually more than three times in excess. Therefore, in lithium solar cells The actual reduction in mass specific capacity is not large, and there is little reduction in volume specific capacity.
(3) High energy density
Higher operating voltage and volumetric specific capacity determine the higher energy density of secondary lithium solar cells. Compared with Ni-Cd batteries and Ni-MH batteries, which are widely used at present, secondary lithium solar cells have the highest energy density and still have great development potential.