Cathode Irreversible Additive with Trigonal LNO for Gas Reduction

The patent changes the crystal structure parameter of lithium nickel oxide from orthorhombic to trigonal system, which fundamentally alters the material's behavior during electrochemical cycling. This parameter change eliminates the harmful structural transitions that occur in the orthorhombic form, preventing impurity and gas generation while maintaining lithium ion supplementation capability.

Instead of accepting the harmful structural changes as inevitable in lithium nickel oxide additives, the patent inverts the approach by selecting a different crystal structure (trigonal vs. orthorhombic) that reverses the problematic behavior. The trigonal structure undergoes reversible structural changes without generating impurities or gas, effectively inverting the harmful effects into beneficial reversible transitions.

The patent modifies the crystal structure parameter from orthorhombic to trigonal system, which changes the nature of structural transitions. The trigonal structure allows reversible structural changes during lithium ion de-intercalation without the irreversible degradation seen in orthorhombic materials, thereby maintaining structural stability while enabling ion transport.

The patent converts the potentially harmful structural changes into a beneficial feature by selecting the trigonal crystal structure. The structural transitions that would normally degrade the material are made reversible in the trigonal system, allowing the material to undergo necessary structural adjustments during cycling without losing stability, thus converting what was a harmful effect into a reversible, beneficial process.

The patent employs lithium nickel oxide with trigonal crystal structure as a sacrificial irreversible additive that deliberately consumes lithium ions during initial cycles to form stable SEI layers. This disposable material sacrifices itself to protect the main cathode active material, allowing the theoretical capacity to be fully utilized in subsequent cycles without further lithium loss.

The trigonal lithium nickel oxide performs preliminary action by undergoing structural changes and consuming lithium ions during initial cycles to create stable solid electrolyte interphase (SEI) layers. This preliminary consumption prevents further lithium loss during normal operation, ensuring that the full theoretical capacity of the cathode material can be utilized throughout the battery's lifecycle.