Enhancement of lithium-ion conductivity for Li_2.2C_0.8B_0.2O₃ by spark plasma sintering

Abstract

Lithium-ion conductivity of Li 2.2 C 0.8 B 0.2 O 3 pellet is 2.1 © 10 ¹6 S cm ¹1 at 30°C after sintering at 450°C by spark-plasma sintering (SPS) process, which is about three times higher than the conductivity of the pellet sintered at 660°C in conventional furnace. The ionic resistance at grain boundary was especially minimalized by SPS process, which would be related to the grain-growth suppression under densification as confirmed by surficial SEM image. Improvement of chargedischarge capacity could be measured at all-solid-state lithium battery assembled by the SPS process (LiCoO 2 Li 2.2 C 0.8 B 0.2 O 3 composite electrolyte/ Li 2.2 C 0.8 B 0.2 O 3 /dry polymer/Li foil) compared with the same compositions of the battery assembled by conventional furnace sintering, which would be due to the enhancement of the ionic transfer at LiCoO 2 /Li 2.2 C 0.8 B 0.2 O 3 hetero interface as well as

Zr- and Ce-doped Li6Y(BO3)3 electrolyte for all-solid-state lithium-ion battery

“… 27 In fact, other Li 3 BO 3 -related families such as Li 2.2 C 0.8 B 0.2 O 3 (ref. 13 and 14 ) and LISICON-Li 3 BO 3 (ref. 16 ) are stable at low voltage, although conductivities are limited to ≈10 −6 S cm −1 at 25 °C.…”

“…For example, Li 3 BO 3 was used as an interfacial additive between LiCoO 2 electrode particles and a garnet-type sintered electrolyte plate, and reversible charge-discharge capacities were demonstrated for the ASSB aer cosintering at 700 C, despite the low conductivity of Li 3 BO 3 (s < 10 À7 S cm À1 at 150 C). 11,12 In a later report, a solid solution of Li 2 CO 3 and Li 3 BO 3 , Li 2.2 C 0.8 B 0.2 O 3 , was described as a superior candidate for assembling the ASSB because of its better conductivity of z10 À6 S cm À1 at 25 C. 13,14 Two other Li 3 BO 3 -related electrolytes-Li 3 BO 3 -Li 2 SO 4 amorphous materials 15 and LISICON-Li 3 BO 3 amorphous materials 16 -were also attractive candidates, but the ASSBs were assembled according to their deformability due to their amorphous character rather than their thermal stability.…”

Progress and Perspective of Glass-Ceramic Solid-State Electrolytes for Lithium Batteries

“…Nagao et al [ 73 ] prepared 90Li 3 BO 3 ·7Li 2 SO 4 ·3Li 2 CO 3 glass-ceramic SSEs by the mechanical ball-milling method with an ionic conductivity of 1 × 10 −5 S·cm −1 at room temperature. Okumura et al [ 74 ] prepared Li 2.2 C 0.8 B 0.2 O 3 glass-ceramic SSEs by the spark plasma sintering (SPS) process. The Li + conductivity at 30 °C was 2.1 × 10 −6 S·cm −1 .…”

Electrochemical Performance and Microstructure Evolution of a Quasi-Solid-State Lithium Battery Prepared by Spark Plasma Sintering

“…Okumura et al prepared LiCoO 2 –Li 2.2 C 0.8 B 0.2 O 3 composite cathode by SPS and assembled a solid-state lithium battery of LiCoO 2 –Li 2.2 C 0.8 B 0.2 O 3 /Li 2.2 C 0.8 B 0.2 O 3 /polymer/Li. The battery delivered an initial discharge capacity of 120 mAh g –1 at 10 μA cm –2 and 60 °C, and the discharge capacity was maintained at 100 mAh g –1 after 10 cycles.…”