Tailoring grain boundary structures and chemistry of Ni-rich layered cathodes for enhanced cycle stability of lithium-ion batteries

Abstract

Corresponding authors: Chongmin.wang@pnnl.gov, xsun9@uwo.ca, Jiguang.zhang@pnnl.gov # These authors contribute equally to this work. ABSTRACT:The biggest challenge for the commercialization of layered structured nickel rich lithium transition metal oxide cathode is the capacity and voltage fading. Resolving this problem over the years follows an incremental progress. In this work, we report our finding of totally a new approach to revolutionize the cycle stability of aggregated cathode particles for lithium ion battery at both room and elevated temperatures. We discover that infusion of a solid electrolyte into the grain boundaries of the cathode secondary particles can dramatically enhance the capacity retention and voltage stability of the battery. We find that the solid electrolyte infused in the boundaries not only acts as a fast channel for Li ion transport, but also most importantly prevents penetration of the liquid electrolyte into the boundaries, consequently eliminating the detrimental factors that include solid-liquid interfacial reaction, intergranular cracking, and layer to spinel phase transformation. The present work, for the first time, reveals unprecedented insight as how the cathode behaves in the case of not contacting with the liquid electrolyte, ultimately points toward a general new route, via grain boundary engineering, for designing of better batteries of both solid-liquid and solid state systems.

3D Cube‐Maze‐Like Li‐Rich Layered Cathodes Assembled from 2D Porous Nanosheets for Enhanced Cycle Stability and Rate Capability of Lithium‐Ion Batteries

“…2020, 10,1903139 the volume ratio of N,N-dimethylformamide (DMF) to deionized water (DI water) (V DMF :V DI water ) is crucial for the morphology of precursor. [17,30,31] As DMF ratio increases to V DMF :V DI water = 1:1, the SHC-P displays a 3D cube-mazelike architecture (the size ranges from 2.0 to 2.5 µm) selfassembled by the 2D nanosheets ( Figure 2a; Figure S1b, Supporting Information). When the V DMF :V DI water is 1:2, the SHM-P demonstrates a microsphere-like structure (the size ranges from 3.0 to 3.5 µm) aggregated by primary nanoparticles of 50-100 nm ( Figure S1a,d, Supporting Information).…”

“…Similarly, SHD-P also shows a solid microsphere in the inner part ( Figure S1i, Supporting Information). [17,31,34] Different from the inner part, the TEM image of outer region of SHD-P is almost transparent corresponding to the random stack of nanosheets on the surface. [17,31,34] Different from the inner part, the TEM image of outer region of SHD-P is almost transparent corresponding to the random stack of nanosheets on the surface.…”

“…[5][6][7][8][9] On the basis of this, extensive efforts have been devoted to develop nanometersized materials and great progresses have been achieved over the past several years, such as construction of nanoplates, [5] nanowires, [10] nanoparticles, [11] and nanorods, [12] which possess a short Li + diffusion pathway thanks to their diminished dimensions. [17,18] Recent reports have evidenced two-dimensional (2D) nanostructure owns the advantages of open electrons and ions transport path, high active surface area, and excellent structure stability by accommodating the drastic volume evolution, which makes it applicable for ultrahigh-rate and cycling-stable lithium storage. [13] In order to address these challenges of nanometer-sized materials, hierarchical micro/nano-materials have been developed recently.…”

Uniform Na+ Doping‐Induced Defects in Li‐ and Mn‐Rich Cathodes for High‐Performance Lithium‐Ion Batteries

“…The SEM images of pristine-LMR, Na-LMR, and Na/SDS-LMR electrodes after 200 cycles are illustrated in Figure S14, Supporting Information. [37] Na-LMR after 200 cycles demonstrates numerous cracks, full of holes and execrably corroded pits, and the surface of secondary particles, unevenly and partially coated by NMO, may experience a severe rupture and cannot deliver protection during prolonged cycles, which might lead to phase transition. [37] Na-LMR after 200 cycles demonstrates numerous cracks, full of holes and execrably corroded pits, and the surface of secondary particles, unevenly and partially coated by NMO, may experience a severe rupture and cannot deliver protection during prolonged cycles, which might lead to phase transition.…”

“…[17] Alkali metal elements like K, [18][19][20] Na, [21,22] alk-earth metal elements Mg [23][24][25][26] and transition elements including Fe, [27,28] Cr, [29] Ti, [30] and La, [31] had been used to optimize the ionic diffusion coefficient and enhance the structure stability. [8,37] Recently, Yan et al [37] have verified that infusing a solid electrolyte (Li 3 PO 4 ) into the grain boundaries of primary particles could dramatically enhance the capacity retention and voltage stability while the surface coating did not work. [32] For instance, Li et al [33] have clearly elucidated that the mechanisms of surface-dopant-coated layer in stabilizing particles was due to the enhancement of TMO bond strength and the alleviation of oxygen loss.…”