Potassium-ion battery

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A potassium-ion battery is a type of battery and analogue to lithium-ion batteries, using potassium ions for charge transfer instead of lithium ions. It was introduced by the Iranian/American chemist Ali Eftekhari (President of the American Nano Society). The device used a potassium compound Prussian blue as the cathode material[1] for its high electrochemical stability.[2] The prototype was successfully used for millions of cycles.

The potassium battery has certain advantages over similar lithium batteries (e.g., lithium-ion batteries): the cell design is simple and both the material and the fabrication procedure are cheaper. The prototype employed a KBF
4
electrolyte though almost all common electrolyte salts can be used. The chemical diffusion coefficient of K+
in the cell is higher than that of Li+
in lithium batteries, due to a smaller Stokes radius of solvated K+
. Since the electrochemical potential of K+
is identical to that of Li+
, the cell potential is similar to that of lithium-ion. Potassium batteries can accept a wide range of cathode materials which can offer rechargeability lower cost. One noticeable advantage is the availability of potassium graphite, which is used as an anode material in some lithium-ion batteries. Its stable structure guarantees a reversible intercalation/de-intercalation of potassium ions under charge/discharge.

In 2005, a potassium battery that uses molten electrolyte of KPF
6
was patented.[3][4] In 2007, Chinese company Starsway Electronics marketed the first potassium battery-powered portable media player as a high-energy device.[5]

Potassium batteries have been proposed for large-scale energy storage given its exceptional cycleability.[6][7]

Researchers demonstrated a potassium-air (K−O2) battery with low overpotential. Its charge/discharge potential gap of about 50 mV is the lowest reported value in metal−air batteries. This provide round-trip energy efficiency of >95%. In comparison, Li-O2 batteries have a much higher overpotential of 1–1.5 V, which results in 60% round-trip efficiency.[8]

See also[edit]

References[edit]

  1. ^ Eftekhari, A (2004). "Potassium secondary cell based on Prussian blue cathode". Journal of Power Sources 126: 221. doi:10.1016/j.jpowsour.2003.08.007. 
  2. ^ Itaya, K; Ataka, T; Toshima, S (1982). "Spectroelectrochemistry and electrochemical preparation method of Prussian Blue modified electrodes". Journal of the American Chemical Society 104 (18): 4767. doi:10.1021/ja00382a006. 
  3. ^ US 20090263717  Ramasubramanian, M; Spotnitz, RM
  4. ^ US 2005017219  Li, W; Kohoma, K; Armand, M; Perron, G
  5. ^ Melanson, D (24 October 2007). "China's Starsway touts potassium battery-powered PMP". Engadget. Retrieved 2011-09-16. 
  6. ^ "New Battery Technology Could Provide Large-Scale Energy Storage for the Grid". 25 November 2011. 
  7. ^ "Battery electrode's 40,000 charge cycles look promising for grid storage". 22 November 2011. 
  8. ^ "A Low-Overpotential Potassium−Oxygen Battery Based on Potassium Superoxide". 

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