MoS ₂ protected LiAl intermetallic compound Li metal anode exhibits a highly reversible Li migration for lithium metal batteries.

Coupling of a Li–In alloy as an anode with Nb ₂ CT _X as an ASEI for practical LMBs.

Rapid development of electronic devices, ranging from personal communication devices to electric mobility solutions, has increased demand for energy storage devices not only in the production volume but also in the product functionality. Among many functional requirements including energy capacity, safety, and short recharge time, one of the major limitations is the short charging time while maintaining the designed capacity. However, even with the most updated lithium-ion battery (LIB) technology, it is well known that fast charging with a high current rate would reduce the lifetime of batteries significantly. Recently, among the many approaches to improve the quick charging performance, a pulse current charging method while keeping the total amount of energy has demonstrated a successful fast recharging of LIB without significantly degrading the battery capacity. The essence of the idea is to stop charging in the middle stage to provide a relaxation period instead of continuously charging at a high current rate. In this study, a comparative study between a conventional charging method with 3C current rate (equivalent to 20 min of charging time) and a pulse current charging with 6C current rate (10 min of charging and 10 min of relaxation time) was carried out. While the conventional charging method showed that the capacity was maintained up to about 200 cycles, the pulse current charging method revealed that the capacity was maintained for more than 450 cycles with a Coulombic efficiency of nearly 100%.

Herein, we unveil the deposition and etch mechanism of GeCl 4 on the SiGe surface. At the high temperature, GeCl 4 is dissociated to GeCl 2 and then worked as a deposition source. Thus, the rate determinant step of surface growth is GeCl 4 dissociation, and a novel precursor that quickly dissociates to GeCl2 will be a proper precursor target to Ge growth at the low-temperature process. Otherwise, at the low temperature, GeCl 4 works as an etching gas by reacts with surface Ge/Si atoms and forms Ge$_{2} H_{n} {Cl}_{6-n}$ or GeSiH$_{n} Cl_{6-n}$ (n=2,3) molecules. From the etch mechanism analysis, the first activation energy of Ge desorption is lower, 65.8 (kcal/mol), than GeCl 4 dissociation (101 kcal/mol), but the etched surface has higher energy, -6.7 (kcal/mol), than the Ge doped, -19.2 (kcal/mol). This energy profile successfully explains the experimental observation, deposition at high temperature, etch at low temperatures. Additionally, we figured out that the GeCl 3 intermediate shows the most tightly bind to surface atoms.