Korea Institute of Industrial Technology

Tdl Co., Ltd.

Min-Young Kim

Ho Sung Kim

Seung Hoon Yang

Duck Rye Chang

Jinsub Lim

Jong Ho Lee

Ha Young Jung

Da Hye Kim

Kyeong Joon Kim

Da-Hye Kim

Seung Woo Choi

The present invention relates to an all-solid-state lithium secondary battery and a method of manufacturing the same. The all-solid-state lithium secondary battery includes a cathode, an anode, and a composite solid electrolyte layer between the cathode and the anode, wherein first and second LLZOs contained respectively in the cathode and the composite solid electrolyte layer are each independently aluminum-doped or undoped LLZO, and the battery of the invention can exhibit improved discharge capacity and cycle characteristics because both the cathode and the composite solid electrolyte layer contain a conductive polymer, a lithium salt and an inorganic ceramic solid electrolyte. The method of the invention enables the all-solid-state lithium secondary battery to be manufactured in a non-sintering manner, thus reducing manufacturing costs and controlling interfacial reactions between active materials, between solid electrolyte particles, and between an electrolyte and an electrode, thereby further reducing the internal resistance of the battery.

All-solid-state lithium secondary battery containing LLZO solid electrolyte and method for preparing same

A method of preparing a gallium-doped LLZO solid electrolyte includes (a) preparing a solid electrolyte precursor slurry by subjecting a mixed solution comprising a metal aqueous solution including lanthanum (La), zirconium (Zr) and gallium (Ga), a complexing agent and a pH controller to coprecipitation; (b) preparing a solid electrolyte precursor by washing and drying the solid electrolyte precursor slurry; (c) preparing a mixture by mixing the solid electrolyte precursor with a lithium source; (d) preparing a gallium-doped LLZO solid electrolyte represented by Chemical Formula 1 below by calcining the mixture at 600 to 1,000&#xb0; C.; and (e) thereafter sintering the solid electrolyte represented by Chemical Formula 1 at 1,000 to 1,300&#xb0; C. By adjusting amounts of starting materials and controlling flow rates of supplied materials, a high-precision cubic structure with improved sintering properties is obtained and ionic conductivity of the solid electrolyte is increased.LiGaLaZrO, (5&#x2264;&#x2264;9, 0&#x3c;&#x2264;4, 2&#x2264;&#x2264;4, 1&#x2264;&#x2264;3).&#x2003;&#x2003;Chemical Formula 1

Method of preparing a gallium-doped LLZO solid electrolyte for an all-solid-state lithium secondary battery

Disclosed is a method of preparing a solid electrolyte, which includes (a) preparing a solid electrolyte precursor slurry by subjecting a mixed solution including a metal precursor solution, containing a lanthanum precursor, a zirconium precursor and an aluminum precursor, a complexing agent, and a pH controller to coprecipitation, (b) preparing a solid electrolyte precursor by washing and drying the solid electrolyte precursor slurry, (c) preparing a mixture by mixing the solid electrolyte precursor with a lithium source, and (d) preparing an aluminum-doped lithium lanthanum zirconium oxide (LLZO) solid electrolyte by calcining the mixture, and which is also capable of adjusting the aluminum content of a starting material to thus control sintering properties and of adjusting the composition of a precursor and a lithium source to thus control the crystal structure, thereby improving the ionic conductivity of the solid electrolyte.

Method for preparing solid electrolyte for all-solid-state lithium secondary battery

Growing community of inventors

Gwangju, South Korea

Min-Young Kim