Stress‐Regulation Design of Lithium Alloy Electrode toward Stable Battery Cycling

Abstract

Metallic tin (Sn) foil is a promising candidate anode for lithium‐ion batteries (LIBs) due to its metallurgical processability and high capacity. However, it suffers low initial Coulombic efficiency and inferior cycling stability due to its uneven alloying/dealloying reactions, large volume change and stress, and fast electrode structural degradation. Herein, we report an undulating LiSn electrode fabricated by a scalable two‐step procedure involving mechanical lithography and chemical prelithiation of Sn foil. With the combination of experimental measurements and chemo‐mechanical simulations, it was revealed the obtained undulating LiSn/Sn electrode could ensure better mechanical stability due to the pre‐swelling state from Sn to LixSn and undulating structure of lithography in comparison with plane Sn, homogenize the electrochemical alloying/dealloying reactions due to the activated surface materials, and compensate Li loss during cycling due to the introduction of excess Li from LixSn, thus enabling enhanced electrochemical performance. Symmetric cells consisting of undulating LiSn/Sn electrode with an active thickness of ∼5 um displayed stable cycling over 1000 h at 1 mA cm‐2 and 1 mAh cm‐2 with a low average overpotential of <15 mV. When paired with commercial LiNi0.6Co0.2Mn0.2O2 (NCM622) cathode with high mass loading of 15.8 mg cm‐2, the full cell demonstrated a high capacity of 2.4 mAh cm‐2 and outstanding cycling stability with 84.9% capacity retention at 0.5 C after 100 cycles. This work presents an advanced LiSn electrode with stress‐regulation design toward high‐performance LIBs, and sheds light on the rational electrode design and processing of other high‐capacity lithium alloy anodes.

Rational Design and Engineering of 1D Heterostructured Porous Sn/CoSnx@C Nanotubes for Superior Lithium Storage

“…Cyclic voltammetry (CV) curves were tested at a scanning rate of 0.01 mV s –1 between 0.01 and 3 V (Figure a). In the first discharge cycle, the two irreversible peaks appearing at 1.4 and 0.78 V can correspond to the reaction between CoSn x and lithium and the formation of the solid electrolyte interface (SEI) film, ,, and the cathode peak at 0.1 V can be attributed to the formation process of Li x Sn alloying . In contrast, in the first charging cycle, the anodic peaks at 0.49, 1.25, and 2.06 V correspond to the dealloying reaction of Li x Sn, the oxidation reaction of Sn, , and the electrochemical reaction of carbon shell, respectively. , After the second cycle, the curves overlap almost completely, indicating outstanding cyclic stability of the Sn/CoSn x @C anode, while the CV curves of the contrast anodes show obvious differences (Figure S13).…”

A Review of Chemically Induced Intercalation and Deintercalation in Battery Materials

“…Materials with large volume changes can benefit from prelithiation by preconditioning the material for subsequent repetitive cycling and reducing stress within the material. Among others, this approach has shown significant success with silicon-based anodes, [84][85][86][87] FeS 2 , [88] and tin [89] among others.…”

“…[115] It was shown that end-of-life LiFePO 4 electrodes could be relithiated chemically, using 1 M solution of LiI in acetonitrile [88] or by using polycyclic aryllithium compounds with adjustable potentials. [89] Thus, lithiated materials could be used in new Li-ion cells, [116] including the demonstration of a full LiFePO 4 lifetime cycle. [117] In a different approach, Gangaja et al explored the delithiation of spent LiFePO 4 for application in Li-ion and Na-ion cells.…”

Design of a potassiophilic 3D conductive scaffold potassium anode (3D-CTZ@K) with dendrite-free and high energy-power density in potassium metal batteries

“…To date, various strategies have been devoted to restrain dendrite growth and alleviate the volume variation, such as optimization of electrolyte compositions, 7,[16][17][18][19][20][21][22][23] design of articial SEI layers, [24][25][26][27][28][29] replacement of K metal with K-Na liquid alloys, [30][31][32][33] and design of 3D scaffolds. [34][35][36][37][38][39] Among these approaches, the design of a 3D scaffold to host K metal can be regarded as the most pragmatic and comprehensive approach to address the root cause since it can inhibit the volume variation and block the K dendrite growth.…”