Enabling 420 Wh kg ⁻¹ Stable Lithium‐Metal Pouch Cells by Lanthanum Doping

Abstract

Under realistic conditions especially for high-energy-density LMBs (>400 Wh kg −1 ), these phenomena will be exacerbated, thereby leading to poor electrochemical performance.Extensive efforts have been devoted to tackling the issues mentioned above, including the modification of surface with protective layers, [7][8][9][10][11] design of current collector structures, [12][13][14][15] introduction of functional electrolyte additives, [16][17][18][19] and application of solid-state electrolytes. [20][21][22] Despite the considerable success achieved in preventing dendrite growth to a certain extent at low Li plating capacities (<2 mAh cm −2 ), challenges still exist at high deposition capacities (>4 mAh cm −2 ). [23] Fundamentally, the formation of Li dendrites undergoes two steps involving nucleation and growth of the Li crystals. [24] As with other metal anodes, Li metal grows continuously on its early-formed nuclei during cycling. The final deposition morphology tightly relies on the preferential crystallographic orientation of Li-metal crystal. [25,26] Intrinsically, Li metal is a body-centered cubic structure, and ( 110), (200), and (211) crystal planes are normally the dominant crystallographic features. Among them, the (110) crystal plane is the most densely packed and thus has the lowest-energy surface, which is regarded as the preferential growth crystal plane of Li-metal anode. [27] Thermodynamically, Li dendrites will eventually be formed if the Li metal keeps growing along the (110) crystal plane. [28,29] Therefore, regulating Li metal's preferential growth orientation is essential. Recently, biomacromolecules have been proven effective in modulating inorganic crystal orientation and inhibiting Li dendrites. [30] Besides, a lateral growth model of Li deposition on single crystal Cu substrates was reported, and the acquired planar Li-metal layer exhibited improved cycle stability and high CE. [31] However, most of the approaches reported to date mainly operated at relatively low Li deposition capacities (<2 mAh cm −2 ), which are insufficient to boost the specific energy beyond 400 Wh kg −1 . To achieve the specific energy up to 400 Wh kg −1 , realistic conditions, including high areal capacity of both anode and cathode (>4 mAh cm −2 ) and lean electrolyte (<3 g Ah −1 ), are necessary. [32,33] Whereas, conditions of current investigations are low mass loading cathode (<3 mAh cm −2 ) and flooded electrolyte (>3 g Ah −1 ), which are far from realizing high cell-level energy Lithium (Li) metal, a promising anode for high-energy-density rechargeable batteries, typically grows along the low-surface energy (110) plane in the plating process, resulting in uncontrollable dendrite growth and unstable interface. Herein, an unexpected Li growth behavior by lanthanum (La) doping is reported: the preferred orientation turns to (200) from (110) plane, enabling 2D nuclei rather than the usual 1D nuclei upon Li deposition and thus forming a dense and dendrite-free morphology even at an ultrahigh areal capacity of 10 mAh...

Enabling isotropic Li growth via Li foil facet-engineering for high-performance Li metal batteries

“…36 Among them, the (110) plane is dominant in bare Li, suggesting that (110) is the mainly exposed crystal plane to accept Li + deposition in the lithiation process. 37 These results well agree with the surface energy calculation results of bare Li electrode that the (110) plane is the preferred orientation with the lowest surface energy. For all Mo-Li electrodes with various Mo ratios, owing to the same bcc crystalline structure of Mo and the small doping amount, Mo-Li electrodes maintained the same crystal structure as Li, without any second phase, such as metallic Mo or Li-Mo intermetallic compounds (Fig.…”

A Stable Triazole‐Based Covalent Gel for Long‐Term Cycling Zn Anode in Zinc‐Ion Batteries

“…During the plating process, the Zn 2+ ions tend to preferentially deposit on the base of zinc dendrites, and the mossy Zn dendrites grow up over time. [63][64][65] At the same time, no significant change was observed for the TEDA@Zn electrode, without the formation of bubbles and dendrites. It suggests that the TEDA gel layer can adjust the rate of Zn 2+ transport and effectively inhibit the formation of Zn dendrites.…”

Toward practical anode-free lithium pouch batteries

“…This causes the rapid deterioration of the cycling performances of anode-free lithium batteries. Compared with coin cells, the larger active electrode area, higher cathode loading, and less electrolyte in pouch cells are more likely to exacerbate the uneven ion concentration distribution and side reactions between the electrolyte and electrode, 97–99 which further deteriorates the morphology and efficiency of electrolyte-induced lithium deposition. This leads to the rapid consumption of active lithium and electrolyte, ultimately accelerating the failure of the pouch battery.…”