Cyclic deterioration and its improvement for Li-rich layered cathode material Li[Ni0.17Li0.2Co0.07Mn0.56]O2

Toward Low-Cost, High-Energy Density, and High-Power Density Lithium-Ion Batteries

“…The phase change also results in a somewhat more complex CEI formation mechanism than that of Ni-rich NMC. 130,131 Strategies to stabilize the surface of Li-rich NMCs include coatings, [132][133][134][135] surface treatments, 126 cycling protocols, 136 synthesis routes, 137,138 and electrolyte additives. 135 Most of these efforts have failed to stop the underlying mechanisms responsible for voltage fade, 135 although compositions that incorporate small amounts of spinel domains into the layered structure show some promise.…”

Relationship between Electrochemical Pre-Treatment and Cycle Performance of a Li-Rich Solid-Solution Layered Li1^|^minus;^|^alpha;[Ni0.18Li0.20+^|^alpha;Co0.03Mn0.58]O2 Cathode for Li-Ion Secondary Batteries

“…These studies revealed that the deterioration begins at an initial charge/discharge potential of 4.5 V, above which microcracks in the crystal surface, distortions in the crystal periodicity, and further non-crystallizations were observed. 20 However, the cathode material crystals treated with the pre-cycling treatment neither cracked nor suffered from any distortions even after 50 charge/discharge cycles. 20 These observations emphasize the importance of the pre-cycling treatment involving a stepwise increase in the charge voltage limit to improve cyclic durability.…”

“…20 However, the cathode material crystals treated with the pre-cycling treatment neither cracked nor suffered from any distortions even after 50 charge/discharge cycles. 20 These observations emphasize the importance of the pre-cycling treatment involving a stepwise increase in the charge voltage limit to improve cyclic durability. Additionally, several of our recent studies have reported on the local structure of an as-prepared Li-rich solid-solution layered cathode material, 21 and the structural 22 and valence state (of Ni, Co, and Mn in the cathode) 23 changes that occurred during its first charge/ discharge cycle.…”

Effect of pressure on the structural properties of Li[Li0.1Ni0.35Mn0.55]O2

“…Additionally, the Li/Ni exchange would also cause structural instability, which could induce a local collapse of the structure and the capacity deterioration of the material during electrochemical cycling. [28][29][30] For the refinement of Li/Ni exchange, the occupancy of each site is fixed to 1, Ni 2+ can be partly incorporated into the Li + site (3b) while the equivalent amount of Li + can be introduced to the transition-metal site of Ni 2+ site (3a) duo to the similarity of the ionic radii of Ni 2+ (0.69 Å) and Li + (0.76 Å). 30 Li/Ni exchange gradually increases in the Fig.…”