Electric field induced crystallization K<6.15>Zn<0.05>B<0.2>Al<0.1>P<0.05>Zr<0.05>Si<1.6>O<7> potassium fast ion conductor and preparation method thereof

Abstract

The invention discloses an electric field induced crystallization K<6.15>Zn<0.05>B<0.2>Al<0.1>P<0.05>Zr<0.05>Si<1.6>O<7> potassium fast ion conductor and a preparation method thereof. Al<3+> and B<3+>are used for partially substituting Si<4+> ions, high-concentration interstitial potassium ions are generated in a crystal, and the reduction of the migration activation energy of potassium ions is facilitated; the electron conductivity of the fast ion conductor is further reduced by doping P<5+>; the size of migration channels of the potassium ions is adjusted by doping B<3+> with a small ionicradius to adapt to the rapid migration of the potassium ions; Zr<4+> is partially doped to form a distorted lattice structure to increase lattice imperfection to facilitate potassium ion conduction; cation vacancies are generated by doping Zn<2+> to increase migratory routes of the potassium ions; and the surface of K6Si2O7 particles is modified during the preparation to form an easy-sintering property. Meanwhile, the introduction of a strong direct current electric field induces crystallization to accelerate the crystallization rate, lower the crystallization temperature and increase the crystal integrity. The synergistic effects enable normal temperature potassium ion conductivity of the potassium fast ion conductor to exceed 5*10<-4> S / cm and to be closer to the potassium ion conductivity of a liquid electrolyte.

Description

technical field [0001] The invention relates to the field of manufacturing a solid potassium fast ion conductor. Background technique [0002] Lithium-ion batteries have absolute advantages such as high volume, high weight-to-energy ratio, high voltage, low self-discharge rate, no memory effect, long cycle life, and high power density. They have an annual share of more than 30 billion US dollars in the global mobile power market and far exceed other The market share of batteries is the most promising chemical power source [Wu Yuping, Wan Chunrong, Jiang Changyin, Lithium-ion Secondary Batteries, Beijing: Chemical Industry Press, 2002.]. At present, most of the lithium-ion secondary batteries at home and abroad use liquid electrolytes. Liquid lithium-ion batteries have some disadvantages, such as: liquid organic electrolytes may leak, and may explode at too high a temperature, causing safety accidents, and cannot be used in some applications. Occasions with high safety requi...

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Problems solved by technology

However, the potassium ion conductors that are essential for the construction of potassium ion all-solid-state batteries are still basically blank.

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