Currently widely used lithium-ion batteries can achieve an energy density of 265 Wh/kg and a capacity of 185 mAh/g, while lithium-sulfur batteries theoretically have an energy density of 2,600 Wh/kg and a capacity of 1,675 mAh/g . In other words, the performance of lithium-sulfur batteries is 10 times better than that of current lithium-ion batteries, and the application prospect is very promising. However, the conversion reaction of sulfur during charging and discharging is slow, resulting in low utilization rate of sulfur and serious dissolution. From Dalian, Chinese Academy of Sciences A research team led by Prof. Jian Liu and Prof. Zhongshuai Wu from the Institute of Chemical Physics (DICP) seems to have recently found a solution: carbon nanospheres as cathodes for lithium-sulfur batteries.
The research was published on April 16 in Advanced Energy Materials, the top international journal in the field of energy materials. These nanospheres work similar to battery cathode nanoreactors, and through Fe1-xS electrocatalyst decoration, can solve the key problem of lithium polysulfide (LiPs) dissolution in lithium-sulfur batteries, knowing that when lithium polysulfide dissolves, the battery loses Sulfur and charge-discharge cycling stability.
These nanospheres have high porosity and can adsorb high sulfur loadings up to 75%, thus avoiding the dissolution of lithium polysulfides. According to the researchers, the capacity of the nanospheres remained stable after 200 charge-discharge cycles at a current density of 0.5 C, with little decay from the initial value of 1070 mAh/g. It is worth mentioning that electric vehicles may face a higher current density, which can reach 4C during fast charging. If scientists can demonstrate that these carbon nanospheres can withstand such high current densities, the resulting lithium-sulfur batteries could potentially offer up to 10 times the range offered by current EV batteries, or half the battery size as a compromise. But get 5 times the range.
In addition, lithium-sulfur batteries have a cost advantage that cannot be underestimated. The materials used in lithium-sulfur batteries are much cheaper than lithium-ion batteries, and sulfur is very abundant in nature, so the price is much lower than that of lithium-ion batteries, and it is expected to achieve the $100/kWh cost of the lifeline of electric vehicles. .
In fact, LFP lithium iron phosphate batteries have had a gratifying development recently, but there is still a certain distance from the above cost line. Electric vehicles have a bright future as battery technology continues to evolve, it just takes a long time to finally arrive. For more information on electric vehicle batteries, please pay attention to the follow-up reports of Sina Auto.
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