Crack Healing Mechanism by Application of Stack Pressure to the Carbon-Based Composite Anode of an All-Solid-State Battery

Mechanical cracks in an all-solid-state battery (ASSB) disrupt lithium-ion conduction pathways; thus, strategies to overcome these are warranted. We found that the stack pressure during charging and discharging heals microcracks in ASSBs, which imparts long-term cyclability in a composite anode made of graphite and solid-state electrolyte (SE, Li6PS5(Cl,Br)). The microcracks were generated when a fabrication pressure of 400 MPa was released but were mechanically bonded under a stack pressure of 40 MPa during cycle tests. They healed further due to the formation of a solid electrolyte interface (SEI) at the binder layer with a thickness of approximately 100 nm between the mechanically contacted graphite and SE. In this crack healing process, the binder served as medium for the movement of Li, S, and O atoms and as the location for the amorphous SEI layer formation. The SEI layer was primarily similar to that of lithium carbonate (Li2CO3), which contained small amounts of sulfur, in terms of the chemical composition and chemical bond. The binder in the ASSB changed to a lithium carbonate SEI regardless of the stack pressure. In the absence of the stack pressure, the ASSB cells maintained the initial structure of the binder and crack in the pristine cell and were degraded with the crucial expansion of the microcracks between electrode materials. The stack pressure was most effective in mitigating the capacity reduction of ASSBs because it induced mechanical and chemical crack healing, which restored the conduction pathways between the graphite and SE particles. The mechanical and structural understanding acquired in this study is expected to provide research angles for sustainable, cost-effective, and high-performance graphite/argyrodite-based ASSB design and fabrication

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Additional file 1 of Clinical significance of HER2-low expression in early breast cancer: a nationwide study from the Korean Breast Cancer Society

Additional file 1: Table S1. Adjuvant treatments according to HER2 status within hormone receptor-positive and triple-negative breast cancer

Clinicopathological characteristics of patients with invasive breast cancer.

Clinicopathological characteristics of patients with invasive breast cancer.</p

Clinicopathological characteristics of hormonal expression subgroups in ILC group.

Clinicopathological characteristics of hormonal expression subgroups in ILC group.</p

Inclusion/Exclusion criteria for patient selection.

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Lithiation Pathway Mechanism of Si‑C Composite Anode Revealed by the Role of Nanopore using <i>In Situ</i> Lithiation

Lithiation kinetics of a Si-C composite anode for high-capacity lithium (Li)-ion batteries were investigated through in situ lithiation and electrochemical C–V measurements using a focused ion beam (FIB). Here, we found in the lithiation procedure that Li migrates sequentially into carbon (C), nanopores, and silicon (Si) in the Si-C composite. In the first lithiation step, Li was intercalated inside C particles while spreading over the surface of the C particles. The second lithiation process occurred through the filling of nanopores existing between electrode particles that consisted of the Si-C composite. The nanopores acted as a Li reservoir during the pore-filling process. Finally, the Si particles were lithiated with a volume expansion of ∼70%, corresponding to a 300% volume expansion of 25 wt % Si particles included in the composite anode. The nanopores did not accommodate a large volume expansion of Si particles, because pore-filling lithiation occurred before the Si lithiation in the charging process. We suggest a design rule related to the role of the nanopores of the Si-C composite anode in LIB systems

Additional file 2 of Clinical significance of HER2-low expression in early breast cancer: a nationwide study from the Korean Breast Cancer Society

Additional file 2: Table S2. Patients characteristics according to HER2 status before and after using IPTW

Additional file 4 of Clinical significance of HER2-low expression in early breast cancer: a nationwide study from the Korean Breast Cancer Society

Additional file 4: Figure S2. Forest plot with hazard ratio showing BCSS according to HER2 IHC score in hormone receptor-positive breast cancer (A) and in triple-negative breast cancer (B)

Lithiation Pathway Mechanism of Si‑C Composite Anode Revealed by the Role of Nanopore using <i>In Situ</i> Lithiation

Lithiation kinetics of a Si-C composite anode for high-capacity lithium (Li)-ion batteries were investigated through in situ lithiation and electrochemical C–V measurements using a focused ion beam (FIB). Here, we found in the lithiation procedure that Li migrates sequentially into carbon (C), nanopores, and silicon (Si) in the Si-C composite. In the first lithiation step, Li was intercalated inside C particles while spreading over the surface of the C particles. The second lithiation process occurred through the filling of nanopores existing between electrode particles that consisted of the Si-C composite. The nanopores acted as a Li reservoir during the pore-filling process. Finally, the Si particles were lithiated with a volume expansion of ∼70%, corresponding to a 300% volume expansion of 25 wt % Si particles included in the composite anode. The nanopores did not accommodate a large volume expansion of Si particles, because pore-filling lithiation occurred before the Si lithiation in the charging process. We suggest a design rule related to the role of the nanopores of the Si-C composite anode in LIB systems